{"id":1069,"date":"2025-05-21T20:27:33","date_gmt":"2025-05-21T12:27:33","guid":{"rendered":"https:\/\/www.hyy.net\/?p=1069"},"modified":"2025-05-21T20:27:33","modified_gmt":"2025-05-21T12:27:33","slug":"asp-net-core-razor-pages-in-action-7-%e4%bd%bf%e7%94%a8%e4%be%9d%e8%b5%96%e5%85%b3%e7%b3%bb%e6%b3%a8%e5%85%a5%e7%ae%a1%e7%90%86%e6%9c%8d%e5%8a%a1","status":"publish","type":"post","link":"https:\/\/diji.net\/?p=1069","title":{"rendered":"ASP.NET Core Razor Pages in Action 7 \u4f7f\u7528\u4f9d\u8d56\u5173\u7cfb\u6ce8\u5165\u7ba1\u7406\u670d\u52a1"},"content":{"rendered":"

ASP.NET Core Razor Pages in Action 7 \u4f7f\u7528\u4f9d\u8d56\u5173\u7cfb\u6ce8\u5165\u7ba1\u7406\u670d\u52a1<\/p>\n

\u672c\u7ae0\u6db5\u76d6<\/h2>\n

\u2022 \u4e86\u89e3\u4f9d\u8d56\u5173\u7cfb\u6ce8\u5165\u7684\u4f5c\u7528
\n\u2022 \u68c0\u67e5 ASP.NET Core \u4e2d\u7684\u4f9d\u8d56\u9879\u6ce8\u5165
\n\u2022 \u521b\u5efa\u548c\u4f7f\u7528\u60a8\u81ea\u5df1\u7684\u670d\u52a1
\n\u2022 \u7ba1\u7406\u670d\u52a1\u751f\u547d\u5468\u671f<\/p>\n

\u4f9d\u8d56\u6ce8\u5165 \uff08DI\uff09 \u662f\u4e00\u79cd\u8f6f\u4ef6\u5de5\u7a0b\u6280\u672f\uff0c\u76ee\u524d\u8bb8\u591a Web \u6846\u67b6\u90fd\u5305\u542b\u5728\u5185\u3002\u5b83\u5b58\u5728\u7684\u7406\u7531\u662f\u5b9e\u73b0\u8f6f\u4ef6\u7ec4\u4ef6\u4e4b\u95f4\u7684\u677e\u6563\u8026\u5408\uff0c\u4ece\u800c\u4f7f\u4ee3\u7801\u4e0d\u90a3\u4e48\u8106\u5f31\u3001\u66f4\u9002\u5e94\u53d8\u5316\u3001\u66f4\u6613\u4e8e\u7ef4\u62a4\u548c\u66f4\u6613\u4e8e\u6d4b\u8bd5\u3002\u5982\u679c\u60a8\u4ee5\u524d\u4f7f\u7528\u8fc7\u4f9d\u8d56\u6ce8\u5165\uff0c\u90a3\u4e48\u6240\u6709\u8fd9\u4e9b\u5bf9\u60a8\u6765\u8bf4\u90fd\u4f1a\u5f88\u719f\u6089\u3002\u5982\u679c\u4f9d\u8d56\u6ce8\u5165\u5bf9\u4f60\u6765\u8bf4\u662f\u4e00\u4e2a\u65b0\u6982\u5ff5\uff0c\u672c\u7ae0\u5c06\u901a\u8fc7\u89e3\u91ca\u5b83\u662f\u4ec0\u4e48\u4ee5\u53ca\u4e3a\u4ec0\u4e48\u4f60\u5e94\u8be5\u5173\u5fc3\u6765\u63d0\u4f9b\u5e2e\u52a9\u3002<\/p>\n

DI \u662f ASP.NET Core \u7684\u6838\u5fc3\u3002\u6574\u4e2a\u6846\u67b6\u4f7f\u7528\u5185\u7f6e\u7684 DI \u529f\u80fd\u6765\u7ba1\u7406\u81ea\u5df1\u7684\u4f9d\u8d56\u9879\u6216\u670d\u52a1\u3002\u5f53\u5e94\u7528\u7a0b\u5e8f\u542f\u52a8\u65f6\uff0c\u670d\u52a1\u5728\u5bb9\u5668\u4e2d\u5168\u5c40\u6ce8\u518c\uff0c\u7136\u540e\u5728\u4f7f\u7528\u8005\u9700\u8981\u65f6\u7531\u5bb9\u5668\u63d0\u4f9b\u3002\u5728\u7b2c 2 \u7ae0\u4e2d\uff0c\u60a8\u9047\u5230\u4e86\u670d\u52a1\u5bb9\u5668\u7684\u4e3b\u5165\u53e3\u70b9\uff0cProgram.cs\u5b83\u901a\u8fc7 WebApplicationBuilder \u7684 Services \u5c5e\u6027\u8fdb\u884c\u8bbf\u95ee\u3002\u60a8\u4f1a\u8bb0\u5f97\uff0c\u7ec4\u6210 Razor Pages \u6846\u67b6\u7684\u670d\u52a1\u662f\u901a\u8fc7 AddRazorPages \u65b9\u6cd5\u6ce8\u518c\u5230\u5bb9\u5668\u4e2d\u7684\uff1a<\/p>\n

var builder = WebApplication.CreateBuilder(args);\n\/\/ Add services to the container.\nbuilder.Services.AddRazorPages();<\/code><\/pre>\n
\u9664\u4e86\u6846\u67b6\u4f7f\u7528\u5176\u5bb9\u5668\u4e4b\u5916\uff0c\u8fd8\u9f13\u52b1\u60a8\u4f7f\u7528\u5b83\u6765\u6ce8\u518c\u81ea\u5df1\u7684\u670d\u52a1\uff0c\u4ee5\u4fbf\u5bb9\u5668\u53ef\u4ee5\u5c06\u5b83\u4eec\u6ce8\u5165\u5230\u4f7f\u7528\u8005\u4e2d\uff0c\u5bb9\u5668\u5c06\u8d1f\u8d23\u4ee3\u8868\u60a8\u7ba1\u7406\u8fd9\u4e9b\u670d\u52a1\u7684\u751f\u547d\u5468\u671f\uff08\u521b\u5efa\u548c\u9500\u6bc1\uff09\u3002\u8fd9\u91cc\u8981\u8bf4\u660e\u7684\u4e00\u4e2a\u5173\u952e\u70b9\u662f\uff0c\u60a8\u4e0d\u9700\u8981\u5c06 DI \u7528\u4e8e\u60a8\u81ea\u5df1\u7684\u670d\u52a1\u3002\u4f46\u662f\uff0c\u60a8\u81f3\u5c11\u5e94\u8be5\u4e86\u89e3 DI \u5728 Razor Pages \u5e94\u7528\u7a0b\u5e8f\u4e2d\u7684\u5de5\u4f5c\u539f\u7406\uff0c\u4ee5\u4fbf\u6839\u636e\u9700\u8981\u81ea\u5b9a\u4e49\u6846\u67b6\u670d\u52a1\u3002<\/p>\n
\u5728\u672c\u7ae0\u7ed3\u675f\u65f6\uff0c\u60a8\u5c06\u4e86\u89e3\u4ec0\u4e48\u662f\u4f9d\u8d56\u9879\u6ce8\u5165\u3001\u5982\u4f55\u5728 Razor Pages \u5e94\u7528\u7a0b\u5e8f\u4e2d\u7ba1\u7406\u5b83\uff0c\u4ee5\u53ca\u5c06 DI \u7528\u4e8e\u60a8\u81ea\u5df1\u7684\u670d\u52a1\u7684\u597d\u5904\u3002\u60a8\u8fd8\u5c06\u66f4\u6e05\u695a\u5730\u4e86\u89e3 Razor Pages \u5e94\u7528\u7a0b\u5e8f\u4e0a\u4e0b\u6587\u4e2d\u7684\u670d\u52a1\u662f\u4ec0\u4e48\u3002\u60a8\u5c06\u521b\u5efa\u4e00\u4e9b\u670d\u52a1\u5e76\u5c06\u5b83\u4eec\u6ce8\u518c\u5230\u4f9d\u8d56\u9879\u6ce8\u5165\u5bb9\u5668\u4e2d\uff0c\u4ee5\u4fbf\u5b83\u4eec\u5728\u6574\u4e2a\u5e94\u7528\u7a0b\u5e8f\u4e2d\u53ef\u7528\u3002<\/p>\n
\u4f8b\u5982\uff0c\u670d\u52a1\u9700\u8981\u7531 DI \u5bb9\u5668\u7ba1\u7406\u5176\u751f\u547d\u5468\u671f\uff0c\u56e0\u6b64\u60a8\u7684\u5e94\u7528\u7a0b\u5e8f\u4e0d\u4f1a\u8017\u5c3d\u5185\u5b58\u3002\u60a8\u4e5f\u4e0d\u5e94\u8be5\u4e0d\u5fc5\u8981\u5730\u5b9e\u4f8b\u5316\u670d\u52a1\uff0c\u5c24\u5176\u662f\u5728\u5e94\u7528\u7a0b\u5e8f\u53ea\u9700\u8981\u4e00\u4e2a\u5b9e\u4f8b\u7684\u60c5\u51b5\u4e0b\u3002\u5728\u672c\u7ae0\u4e2d\uff0c\u60a8\u5c06\u4e86\u89e3\u53ef\u7528\u7684\u4e0d\u540c\u751f\u547d\u5468\u671f\uff0c\u4ee5\u53ca\u5982\u4f55\u5728\u6ce8\u518c\u670d\u52a1\u65f6\u9009\u62e9\u6b63\u786e\u7684\u751f\u547d\u5468\u671f\u3002<\/p>\n
7.1 \u4f9d\u8d56\u6ce8\u5165\u7684\u539f\u56e0<\/h2>\n
\u5728\u6211\u4eec\u4e86\u89e3 ASP.NET Core \u4e2d\u4f9d\u8d56\u9879\u6ce8\u5165\u7684\u57fa\u7840\u77e5\u8bc6\u4e4b\u524d\uff0c\u6211\u4eec\u9700\u8981\u6e05\u695a\u5b83\u6240\u89e3\u51b3\u7684\u95ee\u9898\u7684\u6027\u8d28\u3002\u8be5\u8ba8\u8bba\u6d89\u53ca\u4f7f\u7528\u8f6f\u4ef6\u5de5\u7a0b\u793e\u533a\u5438\u6536\u7684\u672f\u8bed\u6765\u63cf\u8ff0\u539f\u5219\u548c\u6280\u672f\u3002\u8bb8\u591a\u672f\u8bed\u90fd\u975e\u5e38\u62bd\u8c61\uff0c\u7528\u4e8e\u63cf\u8ff0\u62bd\u8c61\u6982\u5ff5\u3002\u56e0\u6b64\uff0c\u5b83\u4eec\u53ef\u80fd\u5f88\u96be\u7406\u89e3\uff0c\u5c24\u5176\u662f\u5bf9\u4e8e\u5b57\u9762\u610f\u4e49\u4e0a\u7684\u601d\u8003\u8005\u3002<\/p>\n
\u6211\u5df2\u7ecf\u5c06\u672f\u8bed\u677e\u6563\u8026\u5408\u4f5c\u4e3a\u8f6f\u4ef6\u5de5\u7a0b\u5e08\u5728\u8bbe\u8ba1\u7cfb\u7edf\u65f6\u5e94\u8be5\u52aa\u529b\u5b9e\u73b0\u7684\u4e3b\u8981\u76ee\u6807\u4e4b\u4e00\u3002\u6211\u5df2\u7ecf\u63d0\u5230\u8fc7\uff0c\u8fd9\u79cd\u677e\u6563\u8026\u5408\u5e94\u8be5\u53d1\u751f\u5728\u7ec4\u4ef6\u4e4b\u95f4\u3002\u5728\u7814\u7a76\u7ec4\u4ef6\u7684\u6027\u8d28\u4e4b\u524d\uff0c\u6211\u60f3\u9000\u540e\u4e00\u6b65\uff0c\u4ece\u8f6f\u4ef6\u5de5\u7a0b\u8bbe\u8ba1\u539f\u5219\u7684\u89d2\u5ea6\u770b\u4e00\u4e0b\u66f4\u5927\u7684\u56fe\u666f\u3002<\/p>\n
7.1.1 \u5355\u4e00\u8d23\u4efb\u539f\u5219<\/h3>\n
\u5728\u8bbe\u8ba1\u7cfb\u7edf\u65f6\uff0c\u60a8\u5e94\u8be5\u8003\u8651\u7684\u4e00\u4e2a\u5173\u952e\u539f\u5219\u662f\u5355\u4e00\u8d23\u4efb\u539f\u5219 \uff08SRP\uff09\u3002\u8fd9\u5c31\u662f S in SOLID\uff0c\u8fd9\u662f\u4e00\u7ec4\u65e8\u5728\u4f7f\u8f6f\u4ef6\u66f4\u6613\u4e8e\u7406\u89e3\u3001\u7075\u6d3b\u548c\u53ef\u7ef4\u62a4\u7684\u539f\u5219\u3002\u4ece\u6839\u672c\u4e0a\u8bf4\uff0cSRP \u89c4\u5b9a\u5e94\u7528\u7a0b\u5e8f\u4e2d\u7684\u4efb\u4f55\u7ec4\u4ef6\u3001\u6a21\u5757\u6216\u670d\u52a1\u90fd\u5e94\u8be5\u53ea\u6709\u4e00\u4e2a\u66f4\u6539\u7684\u7406\u7531\uff1a\u7531\u4e8e\u67d0\u4e9b\u4e1a\u52a1\u539f\u56e0\uff0c\u5176\u552f\u4e00\u804c\u8d23\u9700\u8981\u66f4\u6539\u3002\u5982\u679c\u60a8\u4ee5\u6b64\u539f\u5219\u8003\u8651 PageModel \u7c7b\uff0c\u5219\u53ef\u4ee5\u770b\u5230\u5b83\u8d1f\u8d23\u5904\u7406\u5176\u9875\u9762\u7684 HTTP \u8bf7\u6c42\u3002\u56e0\u6b64\uff0c\u552f\u4e00\u9700\u8981\u66f4\u6539 PageModel \u4e2d\u4ee3\u7801\u4efb\u4f55\u65b9\u9762\u7684\u60c5\u51b5\u662f\u5904\u7406\u8bf7\u6c42\u6240\u9700\u7684\u903b\u8f91\u662f\u5426\u5e94\u66f4\u6539\u3002<\/p>\n
\u5982\u679c\u4f60\u67e5\u770b\u4f60\u5728\u4e0a\u4e00\u7ae0\u4e2d\u653e\u5728\u4e00\u8d77\u7684\u5c5e\u6027\u7ba1\u7406\u5668\u7684 Create \u9875\u9762\u7684 PageModel\uff0c\u4f60\u53ef\u4ee5\u770b\u5230\u8fd9\u4e2a\u539f\u5219\u88ab\u8fdd\u53cd\u4e86\u3002PageModel \u6709\u4e24\u4e2a\u804c\u8d23\uff1a\u5904\u7406\u8bf7\u6c42\u548c\u4ee5\u57ce\u5e02\u96c6\u5408\u7684\u5f62\u5f0f\u4e3a SelectList \u751f\u6210\u6570\u636e\uff08\u56fe 7.1\uff09\u3002<\/p>\n
<\/p>\n
\u56fe 7.1 PageModel \u76ee\u524d\u6709\u4e24\u4e2a\u804c\u8d23\u3002<\/p>\n
\u5728\u4e0b\u4e00\u7ae0\u4e2d\uff0c\u6211\u4eec\u5c06\u4e86\u89e3\u5982\u4f55\u5728 Razor Pages \u5e94\u7528\u7a0b\u5e8f\u4e2d\u4f7f\u7528\u6570\u636e\u5e93\u3002\u60a8\u5c06\u9700\u8981\u901a\u8fc7\u4ece\u6570\u636e\u5e93\u4e2d\u68c0\u7d22\u57ce\u5e02\u9009\u9879\u6765\u66f4\u6539\u57ce\u5e02\u9009\u9879\u7684\u751f\u6210\u65b9\u5f0f\u3002\u8be5\u66f4\u6539\u4e0e PageModel \u7c7b\u7684\u4e3b\u8981\u89d2\u8272 \u2014 \u5904\u7406\u8bf7\u6c42\u65e0\u5173\u3002\u4f46\u662f\uff0c\u6309\u7167\u5f53\u524d\u8bbe\u8ba1\u7684\u65b9\u5f0f\uff0c\u8fc1\u79fb\u5230\u6570\u636e\u5e93\u5c06\u8981\u6c42\u6211\u4eec\u6df1\u5165\u7814\u7a76 CreateModel \u7c7b\u4ee5\u66f4\u6539 GetCityOptions \u65b9\u6cd5\u3002\u6362\u53e5\u8bdd\u8bf4\uff0c\u6570\u636e\u8bbf\u95ee\u7b56\u7565\u7684\u66f4\u6539\u5f53\u524d\u4e3a\u66f4\u6539 PageModel \u7c7b\u63d0\u4f9b\u4e86\u53e6\u4e00\u4e2a\u539f\u56e0\u3002\u5982\u679c\u8981\u9075\u5b88 SRP\uff0c\u5219\u9700\u8981\u5c06\u751f\u6210 City \u6570\u636e\u7684\u903b\u8f91\u79fb\u52a8\u5230\u5176\u81ea\u5df1\u7684\u7ec4\u4ef6\u4e2d\uff0c\u5e76\u8d1f\u8d23\u7ba1\u7406 City \u5b9e\u4f53\u7684\u6570\u636e\u3002<\/p>\n
\u56de\u60f3\u4e00\u4e0b\u7b2c 3 \u7ae0\u4e2d\u8ba8\u8bba\u7684 don't repeat yourself \uff08DRY\uff09 \u539f\u5219\uff0c\u8be5\u539f\u5219\u9f13\u52b1\u60a8\u6700\u5927\u7a0b\u5ea6\u5730\u51cf\u5c11\u4ee3\u7801\u91cd\u590d\u3002\u539f\u5219\u6307\u51fa\uff0c\u6bcf\u4e2a logic \u5728\u7cfb\u7edf\u4e2d\u5e94\u8be5\u53ea\u6709\u4e00\u4e2a\u8868\u793a\u3002\u6211\u4eec\u4e5f\u8fdd\u53cd\u4e86\u8fd9\u4e00\u539f\u5219\u3002\u6211\u4eec\u5728\u4e3b\u9875\u4e2d\u6709\u4ee3\u7801\uff0c\u7528\u4e8e\u4e3a\u5217\u8868\u6846\u793a\u4f8b\u751f\u6210\u57ce\u5e02\uff0c\u4ece\u800c\u6709\u6548\u5730\u590d\u5236\u4e86\u521a\u624d\u5728 CreateModel \u4e2d\u8ba8\u8bba\u7684 GetCityOptions \u4ee3\u7801\u3002\u6b64\u4ee3\u7801\u5e94\u8be5\u662f\u96c6\u4e2d\u7684\uff0c\u5e76\u4e14\u518d\u6b21\u5c06\u5176\u79fb\u52a8\u5230\u81ea\u5df1\u7684\u7ec4\u4ef6\u5c06\u89e3\u51b3\u9519\u8bef\u3002<\/p>\n
\u8ba9\u6211\u4eec\u4ece\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\u5f00\u59cb\u3002\u60a8\u5c06\u6784\u5efa\u4e00\u4e2a\u7ec4\u4ef6\uff0c\u8d1f\u8d23\u751f\u6210 City \u5bf9\u8c61\u7684\u96c6\u5408\uff0c\u5e76\u5c06\u5176\u63d0\u4f9b\u7ed9\u9700\u8981\u5b83\u7684\u5e94\u7528\u7a0b\u5e8f\u7684\u4efb\u4f55\u90e8\u5206\u3002\u7136\u540e\uff0c\u60a8\u5c06\u5728 PageModel \u7c7b\u4e2d\u4f7f\u7528\u8be5\u7ec4\u4ef6\uff0c\u4e3a\u60a8\u76ee\u524d\u6784\u5efa\u7684\u4e00\u4e2a\u9009\u62e9\u5217\u8868\u63d0\u4f9b\u6e90\u6570\u636e\u3002<\/p>\n
\u9996\u5148\uff0c\u5c06\u540d\u4e3a Services \u7684\u65b0\u6587\u4ef6\u5939\u6dfb\u52a0\u5230\u5e94\u7528\u7a0b\u5e8f\u7684\u6839\u76ee\u5f55\u3002\u5728\u6b64\u8303\u56f4\u5185\uff0c\u6dfb\u52a0\u4e00\u4e2a\u540d\u4e3a SimpleCityService.cs \u7684\u65b0 C# \u7c7b\u3002\u4e0b\u9762\u7684\u6e05\u5355\u4e2d\u63d0\u4f9b\u4e86\u8be5\u6587\u4ef6\u7684\u5185\u5bb9\u3002<\/p>\n
\u6e05\u5355 7.1 SimpleCityService \u4ee3\u7801<\/p>\n
using CityBreaks.Models;\n\nnamespace CityBreaks.Services\n{\n    public class SimpleCityService\n    {   \n        public Task<List<City>> GetAllAsync()\n        {\n            return Task.FromResult(Cities);\n        }\n\n        private readonly List<City> Cities = new()\n        {\n            new City { Id = 1, Name = "Amsterdam", Country = new Country { \n                Id = 5, CountryName = "Holland", CountryCode = "nl" \n            } },\n            new City { Id = 2, Name = "Barcelona", Country = new Country { \n                Id = 7, CountryName = "Spain", CountryCode = "es" \n            } },\n            new City { Id = 3, Name = "Berlin", Country = new Country { \n                Id = 4, CountryName = "Germany", CountryCode = "de" \n            } },\n            new City { Id = 4, Name = "Copenhagen", Country = new Country { \n                Id = 2, CountryName = "Denmark", CountryCode = "dk" \n            } },\n            new City { Id = 5, Name = "Dubrovnik", Country = new Country { \n                Id = 1, CountryName = "Croatia", CountryCode = "hr" \n            } },\n            new City { Id = 6, Name = "Edinburgh", Country = new Country { \n                Id = 8, CountryName = "United Kingdom", CountryCode = "gb" \n            } },\n            new City { Id = 7, Name = "London", Country = new Country { \n                Id = 8, CountryName = "United Kingdom", CountryCode = "gb" \n            } },\n            new City { Id = 8, Name = "Madrid", Country = new Country { \n                Id = 7, CountryName = "Spain", CountryCode = "es"\n            } },\n            new City { Id = 9, Name = "New York", Country = new Country { \n                Id = 9, CountryName = "United States", CountryCode = "us" \n            } },\n            new City { Id = 10, Name = "Paris", Country = new Country { \n                Id = 3, CountryName = "France", CountryCode = "fr" \n            } },\n            new City { Id = 11, Name = "Rome", Country = new Country { \n                Id = 6, CountryName = "Italy", CountryCode = "it" \n            } },\n            new City { Id = 12, Name = "Venice", Country = new Country {\n                Id = 6, CountryName = "Italy", CountryCode = "it" \n            } }\n        };\n    }\n}<\/code><\/pre>\n
\u8fd9\u786e\u5b9e\u662f\u4e00\u9879\u7b80\u5355\u7684\u57ce\u5e02\u670d\u52a1\u3002\u6b64\u4ee3\u7801\u6240\u505a\u7684\u53ea\u662f\u751f\u6210\u57ce\u5e02\u53ca\u5176\u6240\u5c5e\u56fd\u5bb6\/\u5730\u533a\u7684\u96c6\u5408\uff0c\u7136\u540e\u901a\u8fc7\u540d\u4e3a GetAllAsync \u7684\u516c\u5171\u65b9\u6cd5\u4f7f\u5b83\u4eec\u53ef\u7528\u3002\u60a8\u6dfb\u52a0\u4e86\u4e00\u4e9b\u770b\u8d77\u6765\u50cf\u5173\u7cfb\u6570\u636e\u5e93\u4e3b\u952e\u7684\u552f\u4e00\u6807\u8bc6\u7b26\u3002\u60a8\u53ef\u4ee5\u5c06\u6b64\u7c7b\u4ee3\u7801\u7528\u4e8e\u6982\u5ff5\u9a8c\u8bc1\u5e94\u7528\u7a0b\u5e8f\uff0c\u6216\u7528\u4f5c\u5355\u5143\u6d4b\u8bd5\u7684\u6d4b\u8bd5\u66ff\u8eab\uff08\u5173\u7cfb\u6570\u636e\u5e93\u7684\u66ff\u4ee3\u54c1\uff09\u3002\u6216\u8005\uff0c\u5982\u679c\u60a8\u66fe\u7ecf\u5199\u8fc7\u4e00\u672c\u4e66\uff0c\u60a8\u53ef\u4ee5\u5c06\u8fd9\u6837\u7684\u4ee3\u7801\u7528\u4f5c\u6f14\u793a\u5e94\u7528\u7a0b\u5e8f\u7684\u4e00\u90e8\u5206\uff0c\u7528\u4e8e\u5b66\u4e60\u76ee\u7684\uff01\u8fd9\u91cc\u552f\u4e00\u6709\u70b9\u5947\u602a\u7684\u662f\uff0cGetAllAsync \u65b9\u6cd5\u8fd4\u56de Task<List<City>><\/code>\u800c\u4e0d\u4ec5\u4ec5\u662f List<City><\/code>\u3002\u8fd9\u662f\u56e0\u4e3a\u60a8\u5c06\u5728\u4e0b\u4e00\u7ae0\u4e2d\u8fc1\u79fb\u5230\u4f7f\u7528\u6570\u636e\u5e93\uff0c\u56e0\u6b64\u60a8\u5e0c\u671b\u6a21\u62df\u6570\u636e\u5e93\u8c03\u7528\uff0c\u8fd9\u4e9b\u8c03\u7528\u901a\u5e38\u5728 ASP.NET Core \u5e94\u7528\u7a0b\u5e8f\u4e2d\u5f02\u6b65\u6267\u884c\u3002\u6211\u5c06\u5728\u4e0b\u4e00\u7ae0\u4e2d\u66f4\u8be6\u7ec6\u5730\u8ba8\u8bba\u8fd9\u4e00\u70b9\u3002<\/p>\n
\u73b0\u5728\u60a8\u5df2\u7ecf\u96c6\u4e2d\u4e86\u57ce\u5e02\u7684\u521b\u5efa\uff0c\u60a8\u53ef\u4ee5\u5728 PropertyManager \\Create.cshtml.cs \u6587\u4ef6\u4e2d\u4f7f\u7528\u60a8\u7684\u65b0\u96f6\u90e8\u4ef6\u3002\u6253\u5f00\u8be5\u9009\u9879\uff0c\u5e76\u66f4\u6539\u73b0\u6709\u5904\u7406\u7a0b\u5e8f\u65b9\u6cd5\u548c GetCityOptions \u65b9\u6cd5\uff0c\u4f7f\u5404\u79cd\u9875\u9762\u5c5e\u6027\u4fdd\u6301\u539f\u6837\u3002\u60a8\u8fd8\u9700\u8981\u4e3a CityBreaks.Services \u6dfb\u52a0 using \u6307\u4ee4\u3002<\/p>\n
\u6e05\u5355 7.2 \u4fee\u6539\u4e86\u4f7f\u7528\u65b0\u7684 SimpleCityService \u7684 Create Property \u9875\u9762<\/p>\n
public async Task OnGetAsync()                                          \u2776\n{    \n    Cities = await GetCityOptions();                                    \u2776\n}    \n\npublic async Task OnPostAsync()                                         \u2776\n{    \n    Cities = await GetCityOptions();                                    \u2776\n    if (ModelState.IsValid)\n    {\n        var city = Cities.First(o => o.Value == SelectedCity.ToString());\n        Message = $"You selected {city.Text} with value of {SelectedCity}";\n    }\n}\n\nprivate async Task<SelectList> GetCityOptions()                         \u2776\n{\n    var service = new SimpleCityService();                              \u2777\n    var cities = await service.GetAllAsync();                           \u2777\n    return new SelectList(cities, nameof(City.Id), \n    \u27a5 nameof(City.Name), null, "Country.CountryName");\n}<\/code><\/pre>\n
\u2776 \u4fee\u6539\u5904\u7406\u7a0b\u5e8f\u65b9\u6cd5\u548c GetCityOptions \u65b9\u6cd5\uff0c\u4f7f\u5b83\u4eec\u5f02\u6b65\u3002
\n\u2777 \u4ece SimpleCityService \u7c7b\u83b7\u53d6\u6570\u636e\uff0c\u800c\u4e0d\u662f\u5728 PageModel \u4e2d\u751f\u6210\u6570\u636e\u3002<\/p>\n
\u9664\u4e86\u8f6c\u6362\u4e3a\u4f7f\u7528\u5f02\u6b65\u65b9\u6cd5\u4e4b\u5916\uff0c\u8fd9\u91cc\u552f\u4e00\u771f\u6b63\u7684\u53d8\u5316\u662f\u751f\u6210\u57ce\u5e02\u96c6\u5408\u7684\u8d23\u4efb\u4e0d\u518d\u662f CreateModel \u7c7b\u7684\u8d23\u4efb\u3002\u8be5\u5de5\u4f5c\u5df2\u59d4\u6d3e\u7ed9\u65b0\u7c7b\uff1aSimpleCityService\u3002CreateModel \u7c7b\u4f9d\u8d56\u4e8e\u6570\u636e\u7684 SimpleCityService\uff0c\u56e0\u6b64 SimpleCityService \u662f CreateModel \u7c7b\u7684\u4f9d\u8d56\u9879\u3002<\/p>\n
7.1.2 \u677e\u8026\u5408<\/h3>\n
\u6211\u76f8\u4fe1\u662f\u53f2\u8482\u592b\u00b7\u53f2\u5bc6\u65af\uff08Steve Smith\uff09\uff0c\u53c8\u540d\u201cArdalis\u201d\uff0c\u4e00\u4f4d\u8457\u540d\u7684 ASP.NET \u6f14\u8bf4\u5bb6\u3001\u4f5c\u5bb6\u548c\u57f9\u8bad\u5e08\uff0c\u9996\u5148\u521b\u9020\u4e86\u201c\u65b0\u5373\u80f6\u6c34\u201d\uff08https:\/\/ardalis.com\/new-is-glue\/\uff09\u8fd9\u53e5\u8bdd\u3002\u4ed6\u5efa\u8bae\uff0c\u65e0\u8bba\u4f55\u65f6\u5728<\/a> C# \u4ee3\u7801\u4e2d\u4f7f\u7528 new \u5173\u952e\u5b57\uff0c\u90fd\u8981\u8003\u8651\u662f\u5426\u5728\u4f7f\u7528\u8005\uff08\u201c\u9ad8\u7ea7\u6a21\u5757\u201d\uff09\u4e0e\u5176\u4f9d\u8d56\u9879\uff08\u201c\u4f4e\u7ea7\u6a21\u5757\u201d\uff09\u4e4b\u95f4\u521b\u5efa\u7d27\u5bc6\u8026\u5408\uff0c\u5982\u679c\u662f\uff0c\u5219\u4ece\u957f\u8fdc\u6765\u770b\u53ef\u80fd\u4f1a\u4ea7\u751f\u4ec0\u4e48\u5f71\u54cd\u3002\u5728\u6b64\u793a\u4f8b\u4e2d\uff0c\u5728\u5c06\u63d0\u4f9b\u57ce\u5e02\u6570\u636e\u7684\u903b\u8f91\u8f6c\u79fb\u5230\u5176\u81ea\u5df1\u7684\u7ec4\u4ef6\u4e2d\u65f6\uff0c\u60a8\u5df2\u6709\u6548\u5730\u5c06 SimpleCityService \u7ec4\u4ef6\u7c98\u9644\u5230 CreateModel \u7c7b\u3002\u8fd9\u4e9b\u53c2\u4e0e\u8005\u4e4b\u95f4\u7684\u5173\u7cfb\u5982\u56fe 7.2 \u6240\u793a\u3002<\/p>\n
<\/p>\n
\u56fe 7.2 SimpleCityServices \u4e0e Create-Model \u7c7b\u7d27\u5bc6\u8026\u5408\u3002<\/p>\n
\u60a8\u5728\u8fd9\u91cc\u8fdd\u53cd\u4e86\u8f6f\u4ef6\u5de5\u7a0b\u539f\u5219\uff0c\u5373\u663e\u5f0f\u4f9d\u8d56\u5173\u7cfb\u539f\u5219\uff0c\u8be5\u539f\u5219\u6307\u51fa\u201c\u65b9\u6cd5\u548c\u7c7b\u5e94\u663e\u5f0f\u8981\u6c42\uff08\u901a\u5e38\u901a\u8fc7\u65b9\u6cd5\u53c2\u6570\u6216\u6784\u9020\u51fd\u6570\u53c2\u6570\uff09\u5b83\u4eec\u9700\u8981\u7684\u4efb\u4f55\u534f\u4f5c\u5bf9\u8c61\uff0c\u4ee5\u4fbf\u6b63\u5e38\u8fd0\u884c\u201d\uff08http:\/\/mng.bz\/9Vzj\uff09\u3002\u60a8\u7684\u534f\u4f5c\u5bf9\u8c61<\/a> SimpleCityService \u662f CreateModel \u7c7b\u7684\u9690\u5f0f\u4f9d\u8d56\u9879\uff0c\u56e0\u4e3a\u53ea\u6709\u5728\u67e5\u770b\u4f7f\u7528\u7c7b\u7684\u6e90\u4ee3\u7801\u65f6\uff0c\u624d\u80fd\u660e\u663e\u5730\u770b\u5230 CreateModel \u7c7b\u4f9d\u8d56\u4e8e SimpleCityService\u3002\u5e94\u907f\u514d\u9690\u5f0f\u4f9d\u8d56\u5173\u7cfb\u3002\u5b83\u4eec\u96be\u4ee5\u6d4b\u8bd5\uff0c\u5e76\u4f7f\u4f7f\u7528\u8005 \uff08CreateModel\uff09 \u66f4\u52a0\u8106\u5f31\u4e14\u96be\u4ee5\u66f4\u6539\u3002<\/p>\n
\u5982\u679c\u4f60\u60f3\u628a\u6570\u636e\u63d0\u4f9b\u8005\u7684\u5b9e\u73b0\u6539\u4e3a\u53e6\u4e00\u4e2a\uff0c\u6bd4\u5982\u8bf4\u4ece\u6570\u636e\u5e93\u83b7\u53d6\u6570\u636e\uff0c\u4f60\u5fc5\u987b\u904d\u5386\u4ee3\u7801\u4e2d\u8c03\u7528 new SimpleCityService\uff08\uff09 \u7684\u6240\u6709\u5730\u65b9\uff0c\u5e76\u6539\u53d8\u5b83\u4ee5\u5f15\u7528\u4f60\u7684\u66ff\u4ee3\u5b9e\u73b0\u3002\u60a8\u5c06\u5728\u4e0b\u4e00\u7ae0\u4e2d\u66f4\u6539\u5b9e\u73b0\u3002\u60a8\u53ef\u80fd\u8ba4\u4e3a\u4f7f\u7528\u5f00\u53d1\u5de5\u5177\u7684 Find and Replace \u529f\u80fd\u53ef\u4ee5\u4f7f\u8fd9\u9879\u5de5\u4f5c\u76f8\u5bf9\u8f7b\u677e\uff0c\u4f46\u8fd9\u4e0d\u662f\u6784\u5efa\u5e94\u7528\u7a0b\u5e8f\u7684\u53ef\u6301\u7eed\u65b9\u5f0f\uff0c\u5c24\u5176\u662f\u5f53\u6709\u66f4\u597d\u7684\u9009\u9879\u53ef\u7528\u4e8e\u4ea4\u6362\u5b9e\u73b0\u65f6\uff0c\u6211\u4eec\u63a5\u4e0b\u6765\u5c06\u4ecb\u7ecd\u8fd9\u4e00\u70b9\u3002<\/p>\n
7.1.3 \u4f9d\u8d56\u5012\u7f6e<\/h3>\n
\u90a3\u4e48\u5982\u4f55\u5b9e\u73b0\u677e\u8026\u5408\u5462\uff1f\u5982\u4f55\u91cd\u65b0\u8bbe\u8ba1\u7ec4\u4ef6\u6216\u670d\u52a1\u7684\u4f7f\u7528\u8005\uff0c\u4f7f\u5b83\u4eec\u4e0d\u518d\u4e0e\u7279\u5b9a\u6216\u5177\u4f53\u7684\u5b9e\u73b0\u7d27\u5bc6\u8026\u5408\uff1f\u4e00\u79cd\u89e3\u51b3\u65b9\u6848\u662f\u4f9d\u8d56\u62bd\u8c61\uff0c\u800c\u4e0d\u662f\u7279\u5b9a\u7684\u5b9e\u73b0\u3002\u8fd9\u79cd\u65b9\u6cd5\u88ab\u79f0\u4e3a\u4f9d\u8d56\u5173\u7cfb\u53cd\u8f6c\u539f\u5219 \uff08DIP\uff09\uff0c\u5b83\u662f SOLID \u9996\u5b57\u6bcd\u7f29\u7565\u8bcd\u4e2d\u7684 D\u3002\u4f9d\u8d56\u5173\u7cfb\u5012\u7f6e\u4e5f\u79f0\u4e3a\u63a7\u5236\u5012\u7f6e \uff08IoC\uff09\u3002<\/p>\n
\u62bd\u8c61\u7c7b\u548c\u63a5\u53e3\u8868\u793a C# \u4e2d\u7684\u62bd\u8c61\u3002\u6839\u636e\u7ecf\u9a8c\uff0c\u60a8\u901a\u5e38\u4f1a\u4f7f\u7528 interfaces \u4f5c\u4e3a\u62bd\u8c61\uff0c\u9664\u975e\u60a8\u6709\u4e00\u4e9b\u5e38\u89c1\u7684\u9ed8\u8ba4\u884c\u4e3a\uff0c\u60a8\u5e0c\u671b\u6240\u6709\u5b9e\u73b0\u5171\u4eab;\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0c\u60a8\u5e94\u8be5\u9009\u62e9\u4e00\u4e2a\u62bd\u8c61\u7c7b\u3002<\/p>\n
\u4f9d\u8d56\u5173\u7cfb\u5012\u7f6e\u539f\u5219\u6307\u51fa\uff0c\u201c\u9ad8\u7ea7\u6a21\u5757\u4e0d\u5e94\u4f9d\u8d56\u4e8e\u4f4e\u7ea7\u6a21\u5757\u3002\u4e24\u8005\u90fd\u5e94\u8be5\u4f9d\u8d56\u4e8e\u62bd\u8c61\u3002\u62bd\u8c61\u4e0d\u5e94\u4f9d\u8d56\u4e8e\u7ec6\u8282\u3002\u7ec6\u8282\u5e94\u8be5\u53d6\u51b3\u4e8e\u62bd\u8c61\u201c\uff08Robert C. Martin\uff1a Agile Software Development\uff0c Principles\uff0c Patterns\uff0c and Practices\uff0c Pearson\uff0c 2002\uff09\u3002<\/p>\n
\u9ad8\u7ea7\u6a21\u5757\u5f80\u5f80\u662f\u670d\u52a1\u7684\u6d88\u8d39\u8005\uff0c\u800c\u4f4e\u7ea7\u6a21\u5757\u5f80\u5f80\u662f\u670d\u52a1\u672c\u8eab\u3002\u56e0\u6b64\uff0cDIP \u7684\u7b2c\u4e00\u90e8\u5206\u6307\u51fa\uff0c\u6d88\u8d39\u8005\u548c\u670d\u52a1\u90fd\u5e94\u8be5\u4f9d\u8d56\u4e8e\u62bd\u8c61\uff0c\u800c\u4e0d\u662f\u6d88\u8d39\u8005\u4f9d\u8d56\u4e8e\u7279\u5b9a\u7684\u670d\u52a1\u5b9e\u73b0\u3002\u5728\u6b64\u793a\u4f8b\u4e2d\uff0c\u62bd\u8c61\u5c06\u662f\u4e00\u4e2a\u63a5\u53e3;Service \u5c06\u5b9e\u73b0\u5b83\uff0c\u5e76\u4e14 Consumer \u5c06\u8c03\u7528\u5b83\uff08\u56fe 7.3\uff09\u3002<\/p>\n
<\/p>\n
\u56fe 7.3 PageModel \u548c SimpleCityService \u4f9d\u8d56\u4e8e\u4e00\u4e2a\u62bd\u8c61\uff1aICityService \u63a5\u53e3\u3002<\/p>\n
\u73b0\u5728\uff0c\u4f9d\u8d56\u5173\u7cfb\u94fe\u5df2\u5012\u7f6e\uff0c\u60a8\u9700\u8981\u8bbe\u8ba1 ICityService \u63a5\u53e3\u3002DIP \u7684\u7b2c\u4e8c\u90e8\u5206\u6307\u51fa\uff0c\u63a5\u53e3\u4e5f\u5e94\u8be5\u4f9d\u8d56\u4e8e\u62bd\u8c61\uff0c\u800c\u4e0d\u662f \u201c\u7ec6\u8282\u201d\u3002\u4e5f\u5c31\u662f\u8bf4\uff0c\u63a5\u53e3\u4e0d\u5e94\u7ed1\u5b9a\u5230\u7279\u5b9a\u7684\u5b9e\u73b0\u3002\u56e0\u6b64\uff0c\u60a8\u7684\u63a5\u53e3\u4e0d\u5e94\u8fd4\u56de\u7279\u5b9a\u4e8e\u5b9e\u73b0\u7684\u7c7b\u578b\uff0c\u4f8b\u5982 DbDataReader\uff0c\u5b83\u4ec5\u9002\u7528\u4e8e\u5173\u7cfb\u6570\u636e\u5e93\u3002\u5b83\u5e94\u8be5\u4f9d\u8d56\u4e8e\u66f4\u901a\u7528\u7684\u7c7b\u578b\uff0c\u5982 List<T><\/code>\u3002\u5e78\u8fd0\u7684\u662f\uff0c\u60a8\u7684 SimpleCityService \u7c7b\u5df2\u7ecf\u8fd9\u6837\u505a\u4e86\u3002\u56e0\u6b64\uff0c\u60a8\u5c06\u57fa\u4e8e\u5176\u73b0\u6709 API \u521b\u5efa\u4e00\u4e2a\u63a5\u53e3\u3002<\/p>\n
\u5c06\u65b0\u7684 C# \u4ee3\u7801\u6587\u4ef6\u6dfb\u52a0\u5230 Services \u6587\u4ef6\u5939\uff0c\u5e76\u5c06\u5176\u547d\u540d\u4e3a ICityService.cs\u3002\u8bf7\u6ce8\u610f\uff0c\u5982\u679c\u60a8\u4f7f\u7528\u7684\u662f Visual Studio\uff0c\u5219 Add...New Item \u5bf9\u8bdd\u6846\u5305\u62ec Interface \uff08\u754c\u9762\uff09 \u9009\u9879\u3002\u5c06\u73b0\u6709\u4ee3\u7801\u66ff\u6362\u4e3a\u4ee5\u4e0b\u5185\u5bb9\u3002<\/p>\n
\u6e05\u5355 7.3 ICityService \u63a5\u53e3<\/p>\n
using CityBreaks.Models;\n\nnamespace CityBreaks.Services\n{\n    public interface ICityService\n    {\n        Task<List<City>> GetAllAsync();\n    }\n}<\/code><\/pre>\n
\u73b0\u5728\u4f60\u9700\u8981\u786e\u4fdd\u4f4e\u7ea7\u7ec4\u4ef6\u4f9d\u8d56\u4e8e\u62bd\u8c61\u3002\u66f4\u6539 SimpleCityService\uff0c\u4f7f\u5176\u5b9e\u73b0\u4ee5\u4e0b\u63a5\u53e3\uff1a<\/p>\n
public class SimpleCityService : ICityService<\/code><\/pre>\n
\u8bf7\u6ce8\u610f\uff0c\u5982\u679c\u60a8\u4f7f\u7528 Visual Studio \u5411\u5bfc\u63d0\u53d6\u63a5\u53e3\uff0c\u5219\u6b64\u6b65\u9aa4\u4e0d\u662f\u5fc5\u9700\u7684\u3002<\/p>\n
\u6700\u540e\u4e00\u6b65\u662f\u8ba9\u9ad8\u7ea7\u6a21\u5757 CreateModel \u7c7b\u4e5f\u4f9d\u8d56\u4e8e\u62bd\u8c61\u3002\u4f60\u600e\u4e48\u505a\u5462\uff1f\u8bf7\u6253\u9f13......\u60a8\u4f7f\u7528\u4f9d\u8d56\u9879\u6ce8\u5165\u3002<\/p>\n
7.1.4 \u4f9d\u8d56\u6ce8\u5165<\/h3>\n
\u4f9d\u8d56\u6ce8\u5165\u662f\u4e00\u79cd\u5e2e\u52a9\u6211\u4eec\u5b9e\u73b0\u4f9d\u8d56\u5012\u7f6e\u7684\u6280\u672f\u3002\u987e\u540d\u601d\u4e49\uff0c\u60a8\u5c06\u4f9d\u8d56\u9879\u6ce8\u5165\u5230\u6d88\u8d39\u6a21\u5757\u4e2d\uff0c\u901a\u5e38\u901a\u8fc7\u5176\u6784\u9020\u51fd\u6570\u4f5c\u4e3a\u53c2\u6570\uff0c\u5e76\u5c06\u5176\u5206\u914d\u7ed9\u79c1\u6709\u5b57\u6bb5\uff0c\u4ee5\u4fbf\u5728\u6d88\u8d39\u7c7b\u4e2d\u4f7f\u7528\u3002\u6b63\u5982\u60a8\u5c06\u8bb0\u5f97\u7684\u90a3\u6837\uff0c\u5c06\u4f9d\u8d56\u9879\u4f5c\u4e3a\u53c2\u6570\u6ce8\u5165\u6784\u9020\u51fd\u6570\u65b9\u6cd5\u6709\u52a9\u4e8e\u6211\u4eec\u9075\u5b88\u663e\u5f0f\u4f9d\u8d56\u9879\u539f\u5219\u3002<\/p>\n
\u4e0b\u9762\u7684\u4ee3\u7801\u6e05\u5355\u663e\u793a\u4e86 CreateModel\uff0c\u5b83\u7ecf\u8fc7\u66f4\u6539\u540e\u5305\u542b\u4e00\u4e2a\u5c06 ICityService \u4f5c\u4e3a\u53c2\u6570\u7684\u663e\u5f0f\u6784\u9020\u51fd\u6570\u3002\u5b83\u4f1a\u5c06\u5176\u5206\u914d\u7ed9\u79c1\u6709\u5b57\u6bb5\uff0c\u4ee5\u4fbf\u5728\u9700\u8981\u65f6\u53ef\u4ee5\u5728\u7c7b\u4e2d\u5f15\u7528\u5b83\u3002<\/p>\n
\u6e05\u5355 7.4 \u901a\u8fc7 CreateModel \u7684\u6784\u9020\u51fd\u6570\u6ce8\u5165 ICityService \u4f9d\u8d56\u9879<\/p>\n
public class CreateModel : PageModel\n{\n    private readonly ICityService _cityService;    \u2776\n    public CreateModel(ICityService cityService)   \u2777\n    {\n        _cityService = cityService;                \u2778\n    }\n    ...\n}<\/code><\/pre>\n
\u2776 \u5411\u7c7b\u6dfb\u52a0\u79c1\u6709\u5b57\u6bb5\u4ee5\u5b58\u50a8\u4f9d\u8d56\u9879\u3002
\n\u2777 \u901a\u8fc7\u6784\u9020\u51fd\u6570\u6ce8\u5165\u4f9d\u8d56\u9879\u3002
\n\u2778 \u5c06\u6ce8\u5165\u7684\u4f9d\u8d56\u9879\u5206\u914d\u7ed9 private \u5b57\u6bb5\u3002<\/p>\n
\u73b0\u5728\uff0c\u60a8\u7684\u4f9d\u8d56\u9879\u662f\u663e\u5f0f\u7684\u3002CreateModel \u7c7b\u6240\u9700\u7684\u534f\u4f5c\u5bf9\u8c61\uff08\u5b9e\u73b0 ICityService \u63a5\u53e3\u7684\u4efb\u4f55\u7c7b\u578b\u7684\uff09\u901a\u8fc7\u5b83\u5728\u7c7b\u7684\u6784\u9020\u51fd\u6570\u4e2d\u7684\u5b58\u5728\u6765\u5411\u5916\u754c\u6807\u8bc6\u3002<\/p>\n
7.2 \u63a7\u5236\u53cd\u8f6c\u5bb9\u5668<\/h2>\n
\u5f53\u7136\uff0c\u5728 C# \u4e2d\uff0c\u60a8\u65e0\u6cd5\u5b9e\u4f8b\u5316\u63a5\u53e3\uff0c\u90a3\u4e48\u6b64\u4ee3\u7801\u600e\u4e48\u6709\u610f\u4e49\u5462\uff1f\u4f20\u9012\u7ed9 constructor \u53c2\u6570\u7684\u5b9e\u9645\u7c7b\u578b\u53ef\u4ee5\u662f\u5b9e\u73b0\u6307\u5b9a\u63a5\u53e3\u7684\u4efb\u4f55\u7c7b\u578b\u3002\u5728\u8fd0\u884c\u65f6\uff0c\u5c06\u5411\u6784\u9020\u51fd\u6570\u63d0\u4f9b\u63a5\u53e3\u7684\u5b9e\u73b0\u3002\u5185\u7f6e\u7684\u4f9d\u8d56\u9879\u6ce8\u5165\u5bb9\u5668\u63d0\u4f9b\u4e86\u5b9e\u73b0\u3002\u5728 Microsoft \u6587\u6863\u4e2d\uff0c\u8fd9\u901a\u5e38\u79f0\u4e3a\u670d\u52a1\u5bb9\u5668\uff0c\u4f46\u66f4\u5e7f\u6cdb\u5730\u8bf4\uff0c\u60a8\u53ef\u80fd\u8fd8\u4f1a\u770b\u5230\u8fd9\u79cd\u7c7b\u578b\u7684\u7ec4\u4ef6\u79f0\u4e3a IoC \u5bb9\u5668\u6216 DI \u5bb9\u5668\u3002<\/p>\n
\u6240\u4ee5\u8fd9\u5c31\u53ea\u5269\u4e0b\u4e00\u4e2a\u95ee\u9898\uff1a\u5bb9\u5668\u5982\u4f55\u77e5\u9053\u8981\u63d0\u4f9b\u54ea\u4e2a\u5b9e\u73b0\uff1f\u7b54\u6848\u662f\uff0c\u60a8\u53ef\u4ee5\u901a\u8fc7\u5728\u5bb9\u5668\u4e2d\u6ce8\u518c\u60a8\u7684\u670d\u52a1\u6765\u544a\u8bc9\u5b83\u3002<\/p>\n
7.2.1 \u670d\u52a1\u6ce8\u518c<\/h3>\n
\u901a\u8fc7\u5c06\u6ce8\u518c\u6dfb\u52a0\u5230 WebApplicationBuilder \u7684 Services \u5c5e\u6027\uff0c\u5728 Program \u7c7b\u4e2d\u8fdb\u884c\u670d\u52a1\u6ce8\u518c\u3002\u60a8\u53ef\u80fd\u8fd8\u8bb0\u5f97\u5728\u7b2c 2 \u7ae0\u4e2d\u8ba8\u8bba\u4f7f\u7528 IMiddleware \u63a5\u53e3\u6784\u5efa\u4e2d\u95f4\u4ef6\u65f6\u770b\u5230\u8fc7\u8fd9\u4e00\u70b9\uff0c\u5c3d\u7ba1\u6211\u5f53\u65f6\u6ca1\u6709\u8be6\u7ec6\u4ecb\u7ecd\u3002\u6807\u51c6 Web \u5e94\u7528\u7a0b\u5e8f\u6a21\u677f\u5df2\u5305\u542b\u901a\u8fc7 AddRazorPages \u65b9\u6cd5\u6ce8\u518c Razor Pages\uff0c\u8be5\u65b9\u6cd5\u8d1f\u8d23\u6ce8\u518c Razor Pages \u6240\u4f9d\u8d56\u7684\u6240\u6709\u670d\u52a1\uff0c\u5305\u62ec\u8d1f\u8d23\u751f\u6210\u548c\u5339\u914d\u8def\u7531\u3001\u5904\u7406\u7a0b\u5e8f\u65b9\u6cd5\u9009\u62e9\u548c\u9875\u9762\u6267\u884c\u7684\u670d\u52a1\uff0c\u4ee5\u53ca Razor \u89c6\u56fe\u5f15\u64ce\u672c\u8eab\u3002<\/p>\n
Services \u5c5e\u6027\u662f IServiceCollection\uff0c\u5b83\u662f\u6846\u67b6\u7684\u670d\u52a1\u5bb9\u5668\u3002\u5b83\u5305\u542b\u4e00\u7ec4 ServiceDescriptor \u5bf9\u8c61\uff0c\u6bcf\u4e2a\u5bf9\u8c61\u90fd\u8868\u793a\u4e00\u4e2a\u5df2\u6ce8\u518c\u7684\u670d\u52a1\u3002\u57fa\u672c\u7684\u6ce8\u518c\u670d\u52a1\u7531\u670d\u52a1\u7c7b\u578b\u3001\u5b9e\u73b0\u548c\u670d\u52a1\u751f\u547d\u5468\u671f\u7ec4\u6210\u3002\u4e0b\u9762\u7684\u6e05\u5355\u663e\u793a\u4e86\u5982\u4f55\u5c06 ICityService \u6ce8\u518c\u4e3a\u65b0\u7684 ServiceDescriptor\u3002<\/p>\n
\u6e05\u5355 7.5 \u5728\u670d\u52a1\u5bb9\u5668\u4e2d\u6ce8\u518c ICityService<\/p>\n
builder.Services.AddRazorPages();\nbuilder.Services.Add(new ServiceDescriptor(typeof(ICityService), typeof(SimpleCityService), ServiceLifetime.Transient));<\/code><\/pre>\n
\u4f46\u662f\uff0c\u60a8\u66f4\u6709\u53ef\u80fd\u4f7f\u7528 IServiceCollection \u4e0a\u63d0\u4f9b\u7684\u7279\u5b9a\u4e8e\u751f\u547d\u5468\u671f\u7684\u6269\u5c55\u65b9\u6cd5\u4e4b\u4e00\uff0c\u8be5\u65b9\u6cd5\u5c06\u670d\u52a1\u7c7b\u578b\u548c\u5b9e\u73b0\u4f5c\u4e3a\u6cdb\u578b\u53c2\u6570\uff08\u56fe 7.4\uff09\u3002<\/p>\n
builder.Services.AddTransient<ICityService, SimpleCityService>();<\/code><\/pre>\n
<\/p>\n
\u56fe 7.4 \u6ce8\u518c\u4f1a\u5bfc\u81f4\u5c06 ServiceDescriptor \u5bf9\u8c61\u6dfb\u52a0\u5230 IServiceCollection \u4e2d\uff0c\u8be5\u5bf9\u8c61\u7531\u670d\u52a1\u7c7b\u578b\u3001\u5b9e\u73b0\u548c\u751f\u5b58\u671f\u7ec4\u6210\u3002<\/p>\n
\u670d\u52a1\u5bb9\u5668\u7684\u5de5\u4f5c\u662f\u5728\u8bf7\u6c42\u670d\u52a1\u7c7b\u578b\u65f6\uff08\u4f8b\u5982\uff0c\u6ce8\u5165\u5230\u6784\u9020\u51fd\u6570\u4e2d\uff09\u63d0\u4f9b\u6b63\u786e\u7684\u5b9e\u73b0\u3002\u6b64\u8fc7\u7a0b\u4e5f\u79f0\u4e3a \u89e3\u51b3\u4f9d\u8d56\u5173\u7cfb\u3002\u56e0\u6b64\uff0c\u5f53\u5bb9\u5668\u770b\u5230\u5bf9 ICityService \u7684\u8bf7\u6c42\u65f6\uff0c\u5b83\u5c06\u63d0\u4f9b SimpleCityService \u7684\u5b9e\u4f8b\uff08\u56fe 7.5\uff09\u3002<\/p>\n
<\/p>\n
\u56fe 7.5 \u5f53\u5bb9\u5668\u770b\u5230\u670d\u52a1\u8bf7\u6c42\u65f6\uff0c\u5b83\u4f1a\u63d0\u4f9b implementation<\/p>\n
7.2.2 \u670d\u52a1\u751f\u547d\u5468\u671f<\/h3>\n
\u670d\u52a1\u5bb9\u5668\u4e0d\u4ec5\u8d1f\u8d23\u89e3\u6790 implementation\u3002\u5b83\u8fd8\u8d1f\u8d23\u7ba1\u7406\u670d\u52a1\u7684\u751f\u547d\u5468\u671f\u3002\u4e5f\u5c31\u662f\u8bf4\uff0c\u5bb9\u5668\u8d1f\u8d23\u521b\u5efa\u670d\u52a1\u5e76\u9500\u6bc1\u670d\u52a1\uff0c\u8fd9\u53d6\u51b3\u4e8e\u670d\u52a1\u6ce8\u518c\u5230\u7684\u751f\u547d\u5468\u671f\u3002\u670d\u52a1\u53ef\u4ee5\u6ce8\u518c\u4e3a\u5177\u6709\u4ee5\u4e0b\u4e09\u4e2a\u751f\u547d\u5468\u671f\u4e4b\u4e00\uff1a<\/p>\n
\u2022  Singleton
\n\u2022  Transient
\n\u2022  Scoped<\/p>\n
\u5bf9\u4e8e\u6bcf\u4e2a\u751f\u547d\u5468\u671f\uff0c\u90fd\u6709\u4e00\u4e2a\u6269\u5c55\u65b9\u6cd5\uff0c\u8be5\u65b9\u6cd5\u4ee5\u5355\u8bcd Add \u5f00\u5934\uff0c\u540e\u8ddf\u751f\u547d\u5468\u671f\u7684\u540d\u79f0\u3002\u4f8b\u5982\uff0c\u60a8\u5df2\u4f7f\u7528 AddTransient \u65b9\u6cd5\u6ce8\u518c\u5177\u6709\u77ac\u6001\u751f\u5b58\u671f\u7684 ICityService\u3002<\/p>\n
\u5355\u4f8b\u670d\u52a1<\/h2>\n
\u4f7f\u7528 AddSingleton \u65b9\u6cd5\u6ce8\u518c\u7684\u670d\u52a1\u5728\u9996\u6b21\u8bf7\u6c42\u670d\u52a1\u65f6\u5b9e\u4f8b\u5316\u4e3a\u5355\u4e00\u5b9e\u4f8b\uff0c\u5e76\u5728\u5bb9\u5668\u7684\u751f\u5b58\u671f\u5185\u4fdd\u7559\uff0c\u8fd9\u901a\u5e38\u4e0e\u6b63\u5728\u8fd0\u884c\u7684\u5e94\u7528\u7a0b\u5e8f\u76f8\u540c\u3002\u987e\u540d\u601d\u4e49\uff0c\u4e00\u4e2a\u5355\u4f8b\u53ea\u80fd\u5b58\u5728\u4e00\u4e2a\u5b9e\u4f8b\u3002\u5b83\u88ab\u91cd\u65b0\u7528\u4e8e\u6240\u6709\u8bf7\u6c42\u3002\u7edd\u5927\u591a\u6570\u6846\u67b6\u670d\u52a1\uff08\u6a21\u578b\u7ed1\u5b9a\u3001\u8def\u7531\u3001\u65e5\u5fd7\u8bb0\u5f55\u7b49\uff09\u90fd\u6ce8\u518c\u4e3a\u5355\u4e00\u5b9e\u4f8b\u3002\u5b83\u4eec\u90fd\u5177\u6709\u76f8\u540c\u7684\u7279\u5f81\uff0c\u56e0\u4e3a\u5b83\u4eec\u6ca1\u6709\u4efb\u4f55\u72b6\u6001\u5e76\u4e14\u662f\u7ebf\u7a0b\u5b89\u5168\u7684\uff0c\u8fd9\u610f\u5473\u7740\u540c\u4e00\u4e2a\u5b9e\u4f8b\u53ef\u4ee5\u8de8\u591a\u4e2a\u7ebf\u7a0b\u4f7f\u7528;\u5904\u7406\u5e76\u53d1\u8bf7\u6c42\u53ef\u80fd\u9700\u8981\u8fd9\u6837\u505a\u3002\u76f8\u540c\u7684\u7279\u5f81\u4e5f\u5fc5\u987b\u9002\u7528\u4e8e\u5355\u4e00\u5b9e\u4f8b\u670d\u52a1\u6240\u4f9d\u8d56\u7684\u4e0e\u670d\u52a1\u4e00\u8d77\u5b9e\u4f8b\u5316\u7684\u4efb\u4f55\u4f9d\u8d56\u9879\u3002<\/p>\n
\u6211\u5c06\u7b80\u8981\u5730\u504f\u79bb\u6211\u4eec\u5f53\u524d\u5e94\u7528\u7a0b\u5e8f\u7684\u4e3b\u8981\u65b9\u5411\uff0c\u901a\u8fc7\u4e00\u4e2a\u7b80\u5355\u7684\u6f14\u793a\u6765\u63a2\u8ba8\u5b83\u662f\u5982\u4f55\u5de5\u4f5c\u7684\u3002\u60a8\u5c06\u521b\u5efa\u4e00\u4e2a\u670d\u52a1\uff0c\u8be5\u670d\u52a1\u516c\u5f00\u5728\u5176\u6784\u9020\u51fd\u6570\u4e2d\u8bbe\u7f6e\u7684\u503c\uff0c\u7136\u540e\u5c06\u8be5\u670d\u52a1\u6ce8\u518c\u4e3a\u5355\u4e00\u5b9e\u4f8b\u3002\u60a8\u5c06\u5bf9\u8be5\u503c\u4f7f\u7528 GUID\uff0c\u56e0\u4e3a\u51e0\u4e4e\u53ef\u4ee5\u80af\u5b9a\uff0c\u6bcf\u6b21\u751f\u6210\u8be5\u503c\u65f6\uff0cGUID \u90fd\u4f1a\u6709\u6240\u4e0d\u540c\u3002\u7136\u540e\uff0c\u60a8\u5c06\u5411\u6d4f\u89c8\u5668\u5448\u73b0\u8be5\u503c\u3002\u60a8\u5c06\u6ce8\u610f\u5230\uff0c\u5f53\u60a8\u5237\u65b0\u9875\u9762\u65f6\uff0c\u8be5\u503c\u4e0d\u4f1a\u66f4\u6539\u3002\u4f7f\u7528\u4ee5\u4e0b\u4ee3\u7801\u5c06\u65b0\u7684 C# \u7c7b\u6dfb\u52a0\u5230\u540d\u4e3a LifetimeDemoService \u7684 Services \u6587\u4ef6\u5939\u4e2d\u3002<\/p>\n
\u6e05\u5355 7.6 LifetimeDemoService \u7c7b<\/p>\n
using System;\nnamespace CityBreaks.Services\n{\n    public class LifetimeDemoService\n    {\n        public LifetimeDemoService()\n        {\n            Value = Guid.NewGuid();\n        }\n        public Guid Value { get; }  \n    }\n}<\/code><\/pre>\n
\u6bcf\u5f53\u8c03\u7528\u7c7b\u6784\u9020\u51fd\u6570\u65f6\uff08\u5373\u5bb9\u5668\u5b9e\u4f8b\u5316\u670d\u52a1\u65f6\uff09\uff0c\u90fd\u4f1a\u8bbe\u7f6e public Value \u5c5e\u6027\u3002\u60a8\u5c06\u6b64\u670d\u52a1\u6ce8\u518c\u4e3a\u5355\u4e00\u5b9e\u4f8b\uff0c\u8fd9\u5e94\u786e\u4fdd\u5b83\u5728\u5e94\u7528\u7a0b\u5e8f\u7684\u751f\u547d\u5468\u671f\u4e2d\u53ea\u5b9e\u4f8b\u5316\u4e00\u6b21\uff1a<\/p>\n
builder.Services.AddRazorPages();\nbuilder.Services.AddTransient<ICityService, SimpleCityService>();\nbuilder.Services.AddSingleton<LifetimeDemoService>();<\/code><\/pre>\n
\u8be5\u670d\u52a1\u6ce8\u518c\u5230 AddSingleton \u65b9\u6cd5\u7684\u4e00\u4e2a\u7248\u672c\uff0c\u8be5\u65b9\u6cd5\u91c7\u7528\u8868\u793a\u5b9e\u73b0\u7684\u5355\u4e2a\u6cdb\u578b\u53c2\u6570\u3002\u6b64\u793a\u4f8b\u6ca1\u6709\u62bd\u8c61\u3002\u8fd9\u4e0d\u662f\u5fc5\u9700\u7684\uff0c\u56e0\u4e3a\u8fd9\u662f\u4e00\u4e2a\u7b80\u5355\u7684\u6f14\u793a\uff0c\u62bd\u8c61\u4f1a\u4e0d\u5fc5\u8981\u5730\u5206\u6563\u5bf9\u540e\u9762\u793a\u4f8b\u7684\u8981\u70b9\u7684\u6ce8\u610f\u529b\u3002\u5728 Pages \u6587\u4ef6\u5939\u4e2d\u521b\u5efa\u4e00\u4e2a\u540d\u4e3a LifetimeDemo.cshtml \u7684\u65b0 Razor \u9875\u9762\uff0c\u5e76\u5728 PageModel \u7c7b\u6587\u4ef6\u4e2d\u4f7f\u7528\u4ee5\u4e0b\u4ee3\u7801\u3002<\/p>\n
\u5217\u8868 7.7 \u7528\u4e8e\u6f14\u793a\u670d\u52a1\u751f\u547d\u5468\u671f\u5982\u4f55\u5de5\u4f5c\u7684 LifetimeDemoModel \u4ee3\u7801<\/p>\n
using CityBreaks.Services;\nusing Microsoft.AspNetCore.Mvc.RazorPages;\n\nnamespace CityBreaks.Pages\n{\n    public class LifetimeDemoModel : PageModel\n    {\n        private readonly LifetimeDemoService _lifetimeDemoService;\n        public LifetimeDemoModel(LifetimeDemoService lifetimeDemoService)\n        {\n            _lifetimeDemoService = lifetimeDemoService; \n        }\n\n        public Guid Value { get; set; }\n        public void OnGet()\n        {\n            Value = _lifetimeDemoService.Value;\n        }\n    }\n}<\/code><\/pre>\n
\u901a\u8fc7\u6dfb\u52a0\u4ee5\u4e0b\u6e05\u5355\u4e2d\u7a81\u51fa\u663e\u793a\u7684\u884c\u6765\u66f4\u6539 Razor \u9875\u9762\u672c\u8eab\u4e2d\u7684\u4ee3\u7801\u3002<\/p>\n
\u5217\u8868 7.8 LifetimeDemo Razor \u9875\u9762<\/p>\n
@page\n@model CityBreaks.Pages.LifetimeDemoModel\n@{\n    ViewData["Title"] = "Lifetime demo";\n}\n<h2>Service Lifetime Demo<\/h2>\n<p>The Singleton service returned @Model.Value<\/p><\/code><\/pre>\n
\u8fd0\u884c\u5e94\u7528\u7a0b\u5e8f\uff0c\u5bfc\u822a\u5230 \/lifetime-demo \uff08\u8bb0\u4f4f KebabPageRouteParameterTransformer \u7684\u6548\u679c\uff09\uff0c\u5e76\u8bb0\u4e0b\u5448\u73b0\u7ed9\u6d4f\u89c8\u5668\u7684\u503c\u3002\u5237\u65b0\u9875\u9762\uff0c\u5e76\u786e\u8ba4\u503c\u4fdd\u6301\u4e0d\u53d8\u3002\u4f7f\u7528\u5176\u4ed6\u6d4f\u89c8\u5668\u8bf7\u6c42\u8be5\u9875\u9762\u3002\u8be5\u503c\u4e0d\u4f1a\u66f4\u6539\u3002\u8fd9\u662f\u56e0\u4e3a\u8be5\u503c\u662f\u5728\u9996\u6b21\u5b9e\u4f8b\u5316\u670d\u52a1\u65f6\u8bbe\u7f6e\u7684\uff0c\u5e76\u4e14\u4f5c\u4e3a\u5355\u4e00\u5b9e\u4f8b\uff0c\u670d\u52a1\u7684\u6240\u6709\u4f7f\u7528\u8005\u5728\u6240\u6709\u8bf7\u6c42\u4e2d\u5171\u4eab\u76f8\u540c\u7684\u670d\u52a1\u5b9e\u4f8b\u3002<\/p>\n
\u77ac\u6001\u670d\u52a1<\/h2>\n
\u4f7f\u7528 AddTransient \u65b9\u6cd5\u6ce8\u518c\u7684\u670d\u52a1\u88ab\u8d4b\u4e88\u77ac\u6001\u751f\u547d\u5468\u671f\uff0c\u8fd9\u610f\u5473\u7740\u6bcf\u6b21\u89e3\u6790\u5b83\u4eec\u65f6\u90fd\u4f1a\u521b\u5efa\u5b83\u4eec\u3002\u8fd9\u4e9b\u7c7b\u578b\u7684\u670d\u52a1\u5e94\u8be5\u662f\u8f7b\u91cf\u7ea7\u7684\u65e0\u72b6\u6001\u670d\u52a1\uff0c\u5176\u5b9e\u4f8b\u5316\u6210\u672c\u76f8\u5bf9\u8f83\u4f4e\u3002\u5f53 service scope \u88ab\u9500\u6bc1\u65f6\uff0c\u5b83\u4eec\u5c06\u88ab\u9500\u6bc1\u3002\u5728 ASP.NET Core \u5e94\u7528\u7a0b\u5e8f\u7684\u4e0a\u4e0b\u6587\u4e2d\uff0c\u8303\u56f4\u5728 HTTP \u8bf7\u6c42\u7ed3\u675f\u65f6\u9500\u6bc1\u3002\u5982\u679c\u60a8\u6709\u4e00\u4e2a\u590d\u6742\u7684\u4f9d\u8d56\u5173\u7cfb\u56fe\uff0c\u5176\u4e2d\u76f8\u540c\u7684\u670d\u52a1\u7c7b\u578b\u88ab\u6ce8\u5165\u5230\u591a\u4e2a\u6784\u9020\u51fd\u6570\u4e2d\uff0c\u5219\u6bcf\u4e2a\u4f7f\u7528\u8005\u90fd\u5c06\u6536\u5230\u81ea\u5df1\u7684\u670d\u52a1\u5b9e\u4f8b\u3002SimpleCityService \u662f\u77ac\u6001\u751f\u5b58\u671f\u7684\u826f\u597d\u5019\u9009\u8005\uff0c\u56e0\u4e3a\u5b83\u6ee1\u8db3\u4e0d\u7ef4\u62a4\u72b6\u6001\u4e14\u5b9e\u4f8b\u5316\u6210\u672c\u4f4e\u7684\u670d\u52a1\u7684\u5b9a\u4e49\u3002<\/p>\n
\u8981\u67e5\u770b\u5176\u5de5\u4f5c\u60c5\u51b5\uff0c\u60a8\u9700\u8981\u5c06\u670d\u52a1\u7684\u7b2c\u4e8c\u4e2a\u5b9e\u4f8b\u6ce8\u5165 PageModel\uff0c\u5e76\u5c06\u5176\u503c\u5448\u73b0\u7ed9\u6d4f\u89c8\u5668\u3002\u5bf9 LifetimeDemoModel \u7c7b\u8fdb\u884c\u4ee5\u4e0b\u66f4\u6539\u3002<\/p>\n
\u6e05\u5355 7.9 \u5411 PageModel \u6ce8\u5165\u7b2c\u4e8c\u4e2a\u670d\u52a1<\/p>\n
private readonly LifetimeDemoService _lifetimeDemoService;\nprivate readonly LifetimeDemoService _secondService;                 \u2776\npublic LifetimeDemoModel(LifetimeDemoService lifetimeDemoService, \n    LifetimeDemoService secondService)                               \u2777\n{\n    _lifetimeDemoService = lifetimeDemoService; \n    _secondService = secondService;                                  \u2778\n}\n\npublic Guid Value { get; set; }\npublic Guid SecondValue { get; set; }                                \u2779\npublic void OnGet()\n{\n    Value = _lifetimeDemoService.Value;\n    SecondValue = _secondService.Value;                              \u277a\n}<\/code><\/pre>\n
\u2776 \u4e3a\u7b2c\u4e8c\u4e2a\u670d\u52a1\u6dfb\u52a0\u79c1\u6709\u5b57\u6bb5\u3002
\n\u2777 \u6ce8\u5165 LifetimeDemoService \u7684\u7b2c\u4e8c\u4e2a\u5b9e\u4f8b\u3002
\n\u2778 \u5c06\u5176\u5206\u914d\u7ed9 private \u5b57\u6bb5\u3002
\n\u2779 \u5411 PageModel \u6dfb\u52a0\u53e6\u4e00\u4e2a\u516c\u5171\u5c5e\u6027\u3002
\n\u277a \u5c06\u5176 value \u8bbe\u7f6e\u4e3a\u7b2c\u4e8c\u4e2a\u670d\u52a1\u7684 Value\u3002<\/p>\n
\u63a5\u4e0b\u6765\uff0c\u66f4\u6539 Razor \u9875\u9762\u4e2d\u5448\u73b0\u670d\u52a1\u503c\u7684\u4ee3\u7801\uff0c\u5982\u4e0b\u6240\u793a\u3002<\/p>\n
\u5217\u8868 7.10 \u6e32\u67d3\u6765\u81ea\u4e24\u4e2a\u670d\u52a1\u7684\u503c<\/p>\n
<p>The first transient service returned @Model.Value<\/p>\n<p>The second transient service returned @Model.SecondValue<\/p><\/code><\/pre>\n
\u6700\u540e\uff0c\u66f4\u6539 Program.cs \u4e2d\u7684\u6ce8\u518c\u4ee5\u4f7f\u7528\u77ac\u6001\u751f\u5b58\u671f\uff1a<\/p>\n
builder.Services.AddTransient<LifetimeDemoService>();<\/code><\/pre>\n
\u8fd0\u884c\u5e94\u7528\u7a0b\u5e8f\uff0c\u5bfc\u822a\u5230 \/lifetime-demo\uff0c\u5e76\u6ce8\u610f\u5448\u73b0\u7ed9\u6d4f\u89c8\u5668\u7684\u503c\u4e0d\u540c\u3002\u6bcf\u6b21\u5237\u65b0\u9875\u9762\u65f6\uff0c\u5b83\u4eec\u90fd\u4f1a\u66f4\u6539\uff0c\u4ece\u800c\u786e\u8ba4\u6bcf\u6b21\u8bf7\u6c42\u65f6\u90fd\u4f1a\u5b9e\u4f8b\u5316\u6bcf\u4e2a\u670d\u52a1\u3002<\/p>\n
\u8303\u56f4\u670d\u52a1<\/h2>\n
\u6700\u540e\u4e00\u4e2a\u751f\u547d\u5468\u671f\u9009\u9879\u662f Scoped \u751f\u547d\u5468\u671f\u3002\u5982\u524d\u6240\u8ff0\uff0c\u5728 ASP.NET Core Web \u5e94\u7528\u7a0b\u5e8f\u4e2d\uff0c\u8303\u56f4\u662f HTTP \u8bf7\u6c42\uff0c\u8fd9\u610f\u5473\u7740\u6bcf\u4e2a HTTP \u8bf7\u6c42\u90fd\u4f1a\u521b\u5efa\u4e00\u6b21\u8303\u56f4\u670d\u52a1\u3002\u5b9e\u9645\u53d1\u751f\u7684\u60c5\u51b5\u662f\uff0c\u4e3a\u6bcf\u4e2a HTTP \u8bf7\u6c42\u521b\u5efa\u4e00\u4e2a\u5bb9\u5668\u5b9e\u4f8b\uff0c\u5e76\u5728\u8bf7\u6c42\u7ed3\u675f\u65f6\u9500\u6bc1\u3002\u4f5c\u7528\u57df\u670d\u52a1\u7531\u6b64\u4f5c\u7528\u57df\u5bb9\u5668\u89e3\u6790\uff0c\u56e0\u6b64\u5728\u4f5c\u7528\u57df\u7ed3\u675f\u65f6\u9500\u6bc1\u5bb9\u5668\u65f6\uff0c\u8fd9\u4e9b\u670d\u52a1\u5c06\u88ab\u9500\u6bc1\u3002\u4f5c\u7528\u57df\u670d\u52a1\u4e0e\u77ac\u6001\u670d\u52a1\u7684\u4e0d\u540c\u4e4b\u5904\u5728\u4e8e\uff0c\u6bcf\u4e2a\u4f5c\u7528\u57df\u53ea\u89e3\u6790\u4f5c\u7528\u57df\u5185\u7684\u670d\u52a1\u7684\u4e00\u4e2a\u5b9e\u4f8b\uff0c\u800c\u77ac\u6001\u670d\u52a1\u7684\u591a\u4e2a\u5b9e\u4f8b\u53ef\u4ee5\u5b9e\u4f8b\u5316\u3002<\/p>\n
\u5b9e\u4f8b\u5316\u540e\uff0c\u4f5c\u7528\u57df\u670d\u52a1\u5c06\u5728\u8303\u56f4 \uff08\u8bf7\u6c42\uff09 \u671f\u95f4\u6839\u636e\u9700\u8981\u591a\u6b21\u91cd\u590d\u4f7f\u7528\uff0c\u5e76\u5728\u8bf7\u6c42\u7ed3\u675f\u65f6\u91ca\u653e\u3002\u6bcf\u4e2a\u8bf7\u6c42\u90fd\u6709\u81ea\u5df1\u7684\u8303\u56f4\u5bb9\u5668\uff0c\u56e0\u6b64\u5bf9\u540c\u4e00\u8d44\u6e90\u7684\u5e76\u53d1\u8bf7\u6c42\u5c06\u4f7f\u7528\u4e0d\u540c\u7684\u5bb9\u5668\u3002<\/p>\n
\u8981\u4e86\u89e3\u5176\u5de5\u4f5c\u539f\u7406\uff0c\u60a8\u9700\u8981\u505a\u7684\u5c31\u662f\u5c06 LifetimeDemoService \u7684\u6ce8\u518c\u66f4\u6539\u4e3a\u4f7f\u7528 AddScoped \u65b9\u6cd5\uff1a<\/p>\n
builder.Services.AddScoped<LifetimeDemoService>();<\/code><\/pre>\n
\u7136\u540e\u66f4\u6539 Razor \u9875\u9762\u4ee5\u5f15\u7528\u8303\u56f4\u5316\u7684\u670d\u52a1\u503c\uff1a<\/p>\n
<p>The first scoped service returned @Model.Value<\/p>\n<p>The second scoped service returned @Model.SecondValue<\/p><\/code><\/pre>\n
\u73b0\u5728\uff0c\u5f53\u60a8\u8fd0\u884c\u5e94\u7528\u7a0b\u5e8f\u65f6\uff0c\u60a8\u5e94\u8be5\u4f1a\u770b\u5230\u4e24\u4e2a\u670d\u52a1\u751f\u6210\u76f8\u540c\u7684\u503c\u3002\u4e00\u65e6 LifetimeDemoService \u88ab\u5b9e\u4f8b\u5316\uff0c\u5b83\u5c31\u4f1a\u5728 HTTP \u8bf7\u6c42\u8303\u56f4\u5185\u9700\u8981\u7684\u4efb\u4f55\u5730\u65b9\u88ab\u91cd\u7528\u3002\u5728\u8fd9\u65b9\u9762\uff0c\u5b83\u7c7b\u4f3c\u4e8e\u5355\u4e00\u5b9e\u4f8b\uff0c\u5176\u8303\u56f4\u9650\u5b9a\u4e3a\u8bf7\u6c42\uff0c\u800c\u4e0d\u662f\u5e94\u7528\u7a0b\u5e8f\u7684\u751f\u547d\u5468\u671f\u3002<\/p>\n
\u4f5c\u7528\u57df\u751f\u547d\u5468\u671f\u6700\u9002\u5408\u4e8e\u5b9e\u4f8b\u5316\u6210\u672c\u9ad8\u6602\u548c\/\u6216\u9700\u8981\u5728\u8bf7\u6c42\u671f\u95f4\u4fdd\u6301\u72b6\u6001\u7684\u670d\u52a1\u3002\u5728 Razor Pages \u5e94\u7528\u7a0b\u5e8f\u4e2d\uff0c\u53d7\u76ca\u4e8e\u4f5c\u7528\u57df\u751f\u5b58\u671f\u7684\u6700\u5e38\u7528\u670d\u52a1\u4e4b\u4e00\u662f\u5b9e\u4f53\u6846\u67b6 DbContext\uff0c\u6211\u4eec\u5c06\u5728\u4e0b\u4e00\u7ae0\u4e2d\u66f4\u8be6\u7ec6\u5730\u4ecb\u7ecd\u5b83\u3002DbContext \u6ee1\u8db3\u8fd9\u4e24\u4e2a\u6761\u4ef6\uff0c\u56e0\u4e3a\u5b83\u521b\u5efa\u4e0e\u5916\u90e8\u8d44\u6e90\uff08\u6570\u636e\u5e93\uff09\u7684\u8fde\u63a5\uff0c\u5e76\u4e14\u5b83\u53ef\u80fd\u9700\u8981\u7ef4\u62a4\u6709\u5173\u4ece\u6570\u636e\u5e93\u4e2d\u68c0\u7d22\u7684\u6570\u636e\u7684\u4fe1\u606f\u3002<\/p>\n
7.2.3 \u6355\u83b7\u4f9d\u8d56\u9879<\/h3>\n
\u5728\u4e3a\u670d\u52a1\u9009\u62e9\u751f\u547d\u5468\u671f\u65f6\uff0c\u60a8\u8fd8\u5e94\u8003\u8651\u670d\u52a1\u6240\u4f9d\u8d56\u7684\u4efb\u4f55\u4f9d\u8d56\u9879\u7684\u751f\u547d\u5468\u671f\u3002\u4f8b\u5982\uff0c\u5982\u679c\u4f9d\u8d56\u9879\u662f\u5df2\u6ce8\u518c\u5230\u4f5c\u7528\u57df\u5185\u751f\u5b58\u671f\u7684 DbContext\uff0c\u5219\u5e94\u786e\u4fdd\u60a8\u7684\u670d\u52a1\u4e5f\u6ce8\u518c\u5230\u4f5c\u7528\u57df\u5185\u751f\u5b58\u671f\u3002\u5426\u5219\uff0c\u60a8\u6700\u7ec8\u53ef\u80fd\u4f1a\u9047\u5230\u79f0\u4e3a\u6355\u83b7\u4f9d\u8d56\u9879\u7684\u95ee\u9898\u3002\u5f53\u4f9d\u8d56\u9879\u6ce8\u518c\u7684\u751f\u547d\u5468\u671f\u77ed\u4e8e\u5176\u4f7f\u7528\u8005\u65f6\uff0c\u4f1a\u51fa\u73b0\u6b64\u95ee\u9898\u3002\u5982\u679c\u5c1d\u8bd5\u4ece\u5355\u4e00\u5b9e\u4f8b\u4e2d\u4f7f\u7528\u4f5c\u7528\u57df\u5185\u670d\u52a1\uff0c\u5219 DI \u5bb9\u5668\u5c06\u5f15\u53d1 InvalidOperationException\uff0c\u4f46\u4e0d\u4f1a\u6536\u5230\u6b64\u7c7b\u4fdd\u62a4\uff0c\u4ee5\u9632\u6b62\u4ece\u5355\u4e00\u5b9e\u4f8b\u4e2d\u4f7f\u7528\u6682\u65f6\u6027\u670d\u52a1\u3002\u5982\u679c\u5c06\u4e34\u65f6\u670d\u52a1\u6ce8\u5165\u53e6\u4e00\u4e2a\u670d\u52a1\uff0c\u7136\u540e\u6ce8\u518c\u4e3a\u5355\u4e00\u5b9e\u4f8b\uff0c\u5219\u4f9d\u8d56\u9879\u5b9e\u9645\u4e0a\u4e5f\u4f1a\u6210\u4e3a\u5355\u4e00\u5b9e\u4f8b\uff0c\u56e0\u4e3a\u5728\u5e94\u7528\u7a0b\u5e8f\u7684\u751f\u547d\u5468\u671f\u5185\uff0c\u4f7f\u7528\u670d\u52a1\u7684\u6784\u9020\u51fd\u6570\u53ea\u4f1a\u88ab\u8c03\u7528\u4e00\u6b21\uff0c\u5e76\u4e14\u53ea\u4f1a\u5728\u5e94\u7528\u7a0b\u5e8f\u505c\u6b62\u65f6\u9500\u6bc1\u3002<\/p>\n
\u8ba9\u6211\u4eec\u6765\u770b\u770b\u8fd9\u4e2a\uff0c\u8fd9\u6837\u4f60\u5c31\u53ef\u4ee5\u6e05\u695a\u5730\u7406\u89e3\u5b83\u3002\u5c06\u4ee5\u4e0b\u4ee3\u7801\u4f5c\u4e3a\u65b0\u7684 C# \u7c7b\u6dfb\u52a0\u5230 Services \u6587\u4ef6\u5939\u4e2d\u3002<\/p>\n
\u6e05\u5355 7.11 SingletonService \u7c7b<\/p>\n
namespace CityBreaks.Services\n{\n    public class SingletonService\n    {\n        private readonly LifetimeDemoService _dependency;\n        public SingletonService(LifetimeDemoService dependency)\n        {\n           _dependency = dependency;\n        }\n        public Guid DependencyValue => _dependency.Value;\n    }\n}<\/code><\/pre>\n
\u4ee3\u7801\u5f88\u7b80\u5355;SingletonService \u7c7b\u5c06\u60a8\u73b0\u6709\u7684 LifetimeDemoService \u4f5c\u4e3a\u4f9d\u8d56\u9879\uff0c\u5e76\u4f7f\u7528\u5b83\u6765\u751f\u6210\u503c\u3002\u73b0\u5728\u4f60\u9700\u8981\u5c06 SingletonService \u6ce8\u518c\u4e3a\u5355\u4e00\u5b9e\u4f8b\uff0c\u540c\u65f6\u8ba9 LifetimeDemoService \u6ce8\u518c\u4e3a\u77ac\u6001\u751f\u547d\u5468\u671f\uff1a<\/p>\n
builder.Services.AddTransient<LifetimeDemoService>();\nbuilder.Services.AddSingleton<SingletonService>();<\/code><\/pre>\n
\u66f4\u6539 Razor \u9875\u9762\u4e2d\u7684\u6807\u8bb0\u4ee5\u8f93\u51fa\u4ee5\u4e0b\u5185\u5bb9\uff1a<\/p>\n
<p>The singleton service's transient dependency returned @Model.Value<\/p><\/code><\/pre>\n
\u8fd0\u884c\u9875\u9762\u5e76\u5237\u65b0\u5b83\u3002\u8bf7\u6ce8\u610f\uff0c\u8be5\u503c\u6c38\u8fdc\u4e0d\u4f1a\u66f4\u6539\u3002\u4f60\u4e0d\u4f1a\u5728\u6bcf\u4e2a\u8bf7\u6c42\u4e0a\u83b7\u5f97 LifetimeDemoService \u7684\u65b0\u5b9e\u4f8b\uff0c\u56e0\u4e3a\u4f7f\u7528\u8005\u7684\u6784\u9020\u51fd\u6570\u6ca1\u6709\u88ab\u8c03\u7528\uff0c\u56e0\u4e3a\u5b83\u662f\u4e00\u4e2a\u5355\u4e00\u5b9e\u4f8b\u3002<\/p>\n
7.2.4 \u5176\u4ed6\u670d\u52a1\u6ce8\u518c\u9009\u9879<\/h3>\n
\u4e0a\u8ff0\u793a\u4f8b\u4f7f\u7528\u4e86 Add[LIFETIME] \u65b9\u6cd5\u4e4b\u4e00\uff0c\u8be5\u65b9\u6cd5\u91c7\u7528\u4e24\u4e2a\u6cdb\u578b\u53c2\u6570 \u2014 \u7b2c\u4e00\u4e2a\u53c2\u6570\u8868\u793a\u670d\u52a1\u7c7b\u578b\uff0c\u7b2c\u4e8c\u4e2a\u53c2\u6570\u8868\u793a\u5b9e\u73b0\u3002\u8fd9\u662f\u60a8\u53ef\u80fd\u6700\u5e38\u4f7f\u7528\u7684\u6a21\u5f0f\u3002\u6211\u4eec\u8fd8\u67e5\u770b\u4e86\u91c7\u7528\u5b9e\u73b0\u7684 Add[LIFETIME] \u65b9\u6cd5\u7684\u7248\u672c\u3002\u5728\u8fd9\u91cc\uff0c\u6211\u4eec\u5c06\u56de\u987e\u4e00\u4e9b\u63d0\u4f9b\u989d\u5916\u529f\u80fd\u7684\u5176\u4ed6\u6ce8\u518c\u9009\u9879\u3002<\/p>\n
\u60f3\u8c61\u4e00\u4e0b\u4f60\u7684 SimpleCityService \u9700\u8981\u4f20\u9012\u7ed9\u5b83\u4e00\u4e9b\u6784\u9020\u51fd\u6570\u53c2\u6570\u3002\u60a8\u53ef\u4ee5\u901a\u8fc7\u4f20\u5165\u5b9a\u4e49\u8981\u4f20\u9012\u7684\u53c2\u6570\u7684\u5de5\u5382\u6765\u505a\u5230\u8fd9\u4e00\u70b9\uff1a<\/p>\n
builder.Services.AddTransient<ICityService>(provider => new \n\u27a5 SimpleCityService(args));<\/code><\/pre>\n
\u5982\u679c\u6784\u9020\u51fd\u6570\u53c2\u6570\u5305\u542b\u6765\u81ea\u5bb9\u5668\u7684\u4f9d\u8d56\u9879\uff0c\u5219\u5de5\u5382\u5c06\u63d0\u4f9b\u5bf9\u8be5\u670d\u52a1\u7684\u8bbf\u95ee\uff0c\u56e0\u6b64\u60a8\u53ef\u4ee5\u89e3\u6790\u4f9d\u8d56\u9879\u3002\u4e0b\u9762\u7684\u793a\u4f8b\u6f14\u793a SimpleCityService \u4f9d\u8d56\u4e8e IMyService \u548c args \u7684\u5b9e\u73b0\u65f6\uff0c\u5176\u5de5\u4f5c\u539f\u7406\u3002\u4f7f\u7528 IServiceProvider GetService \u65b9\u6cd5\u89e3\u6790\u4f9d\u8d56\u9879\u3002\u5728\u672c\u7ae0\u672b\u5c3e\uff0c\u6211\u4eec\u5c06\u4ecb\u7ecd\u76f4\u63a5\u4ece\u670d\u52a1\u63d0\u4f9b\u5546\u8bbf\u95ee\u670d\u52a1\u7684\u5176\u4ed6\u65b9\u6cd5\uff1a<\/p>\n
builder.Services.AddTransient(provider => \n    new SimpleCityService(args, provider.GetService<IMyService>())\n);<\/code><\/pre>\n
factory \u9009\u9879\u662f\u9996\u9009\u9009\u9879\uff0c\u56e0\u4e3a\u5b83\u5c06\u66f4\u65b0\u6216\u6fc0\u6d3b\u670d\u52a1\u7684\u8d23\u4efb\u4ea4\u7ed9\u4e86\u670d\u52a1\u5bb9\u5668\u3002\u5982\u679c\u5bb9\u5668\u8d1f\u8d23\u670d\u52a1\u6fc0\u6d3b\uff0c\u5b83\u8fd8\u8d1f\u8d23\u670d\u52a1\u5904\u7f6e\u3002\u8fd8\u6709\u4e00\u79cd\u9002\u7528\u4e8e\u5355\u4f8b\u670d\u52a1\u7684\u66ff\u4ee3\u65b9\u6cd5\uff0c\u8be5\u65b9\u6cd5\u6d89\u53ca\u4f20\u5165\u6784\u9020\u7684\u670d\u52a1\uff1a<\/p>\n
builder.Services.AddSingleton<IMyService>(new MyService(args));<\/code><\/pre>\n
\u5f53\u60a8\u4f7f\u7528\u6b64\u65b9\u6cd5\u6ce8\u518c\u670d\u52a1\u65f6\uff0c\u60a8\u4e5f\u5fc5\u987b\u5bf9\u5176\u5904\u7f6e\u8d1f\u8d23\u3002\u5982\u679c\u4f7f\u7528 implementation-only \u9009\u9879\u4f20\u5165\u6784\u9020\u7684\u670d\u52a1\uff0c\u5219\u60c5\u51b5\u4e5f\u662f\u5982\u6b64\uff1a<\/p>\n
builder.Services.AddSingleton(new MyService(args));<\/code><\/pre>\n
7.2.5 \u6ce8\u518c\u591a\u4e2a implementation<\/h3>\n
\u53ef\u4ee5\u901a\u8fc7\u91cd\u590d\u5177\u6709\u76f8\u540c\u670d\u52a1\u7c7b\u578b\u4f46\u4e0d\u540c\u5b9e\u73b0\u7684\u76f8\u5173 Add[LIFETIME] \u65b9\u6cd5\u6765\u6ce8\u518c\u670d\u52a1\u7684\u591a\u4e2a\u5b9e\u73b0\uff1a<\/p>\n
builder.Services.AddTransient<ICityService, SimpleCityService>();\nbuilder.Services.AddTransient<ICityService, CityService>();<\/code><\/pre>\n
\u8fd9\u5c31\u63d0\u51fa\u4e86\u4e00\u4e2a\u660e\u663e\u7684\u95ee\u9898\uff1a\u5f53\u5b83\u7684\u62bd\u8c61\u88ab\u6ce8\u5165\u5230\u6784\u9020\u51fd\u6570\u4e2d\u65f6\uff0c\u54ea\u4e00\u4e2a\u4f1a\u5f97\u5230\u89e3\u51b3\uff1f\u8be5\u95ee\u9898\u7684\u7b54\u6848\u662f\u60a8\u6ce8\u518c\u7684\u6700\u540e\u4e00\u4e2a\u3002\u6240\u4ee5\u53e6\u4e00\u4e2a\u95ee\u9898\u51fa\u73b0\u4e86\uff1a\u6ce8\u5165\u591a\u4e2a implementation\u7684\u80fd\u529b\u6709\u4ec0\u4e48\u7528\uff1f<\/p>\n
\u5047\u8bbe\u60a8\u6709\u591a\u4e2a\u4e0d\u540c\u7684\u670d\u52a1\u5b9e\u73b0\uff0c\u4f46\u60a8\u4f9d\u8d56\u8fd0\u884c\u65f6\u6570\u636e\u6765\u786e\u5b9a\u4f7f\u7528\u54ea\u4e2a\u5b9e\u73b0\u3002\u4f8b\u5982\uff0c\u60a8\u53ef\u80fd\u5e0c\u671b\u6839\u636e\u8bbf\u5ba2\u7684\u4f4d\u7f6e\u8ba1\u7b97\u4ef7\u683c\u3001\u7a0e\u8d39\u548c\u6298\u6263\u3002\u4f60\u53ef\u4ee5\u4e3a\u4f60\u670d\u52a1\u7684\u6bcf\u4e2a\u4f4d\u7f6e\u586b\u5145\u4e00\u4e2a\u670d\u52a1\u7684\u6761\u4ef6\u4ee3\u7801\uff0c\u4f46\u4f60\u53ef\u4ee5\u60f3\u8c61\u8fd9\u79cd\u65b9\u6cd5\u5f88\u5feb\u5c31\u4f1a\u53d8\u5f97\u975e\u5e38\u6df7\u4e71\uff0c\u5c24\u5176\u662f\u5728\u8ba1\u7b97\u5f88\u590d\u6742\u7684\u60c5\u51b5\u4e0b\u3002\u4f8b\u5982\uff0c\u5982\u679c\u60a8\u9700\u8981\u66f4\u65b0\u4ee3\u7801\u4ee5\u53cd\u6620\u4e00\u4e2a\u5730\u533a\u7684\u6cd5\u5f8b\u53d8\u5316\uff0c\u60a8\u4e5f\u53ef\u4ee5\u60f3\u8c61\u7ef4\u62a4\u95ee\u9898\u3002\u8fd9\u6709\u53ef\u80fd\u65e0\u610f\u4e2d\u66f4\u6539\u5176\u4ed6\u4f4d\u7f6e\u7684\u4ee3\u7801\uff0c\u5e76\u5f15\u5165\u4e0e\u60a8\u9700\u8981\u8fdb\u884c\u7684\u66f4\u6539\u65e0\u5173\u7684 bug\u3002<\/p>\n
\u76f8\u53cd\uff0c\u60a8\u53ef\u4ee5\u4e3a\u6bcf\u4e2a\u4f4d\u7f6e\u63d0\u4f9b\u5355\u72ec\u7684\u5b9e\u65bd\u3002\u8bf7\u8003\u8651\u4ee5\u4e0b\u7b80\u5355\u63a5\u53e3\uff1aIPriceService\u3002<\/p>\n
\u793a\u4f8b 7.12 IPriceService \u63a5\u53e3<\/p>\n
public interface IPriceService\n{\n    string GetLocation();\n    double CalculatePrice();\n}<\/code><\/pre>\n
\u6b64\u63a5\u53e3\u5b9a\u4e49\u4e86\u4e24\u4e2a\u65b9\u6cd5\uff1a\u4e00\u4e2a\u8fd4\u56de\u9002\u7528\u4e8e\u4efb\u4f55\u7279\u5b9a\u5b9e\u73b0\u7684\u4f4d\u7f6e\uff0c\u53e6\u4e00\u4e2a\u8868\u793a\u8ba1\u7b97\u4ef7\u683c\u7684\u903b\u8f91\u3002\u5047\u8bbe\u6b64\u670d\u52a1\u5b9a\u4e49\u7684\u6bcf\u4e2a\u5b9e\u73b0\u90fd\u8fd4\u56de\u60a8\u5df2\u7ecf\u77e5\u9053\u7684 ISO 3166-1 Alpha-2 \u4ee3\u7801\uff0c\u4f46\u9ed8\u8ba4\u4ef7\u683c\u670d\u52a1\u9664\u5916\uff0c\u5b83\u8fd4\u56de\u201cXX\u201d\u3002\u7f8e\u56fd\u7248\u672c\u5982\u6e05\u5355 7.13 \u6240\u793a\u3002\u5176\u4ed6\u9009\u9879\u53ef\u5728\u672c\u8282\u968f\u9644\u7684\u4e0b\u8f7d \uff08http:\/\/mng.bz\/o54p<\/a>\uff09 \u4e2d\u627e\u5230\u3002<\/p>\n
\u6e05\u5355 7.13 \u7f8e\u56fd IPriceService \u7684\u793a\u4f8b\u5b9e\u73b0<\/p>\n
public class UsPriceService : IPriceService\n{\n    public string GetLocation() => "us";\n    public double CalculatePrice()\n    {\n        ...\n    }\n}<\/code><\/pre>\n
\u60a8\u53ef\u4ee5\u5411\u670d\u52a1\u5bb9\u5668\u6ce8\u518c\u5404\u79cd\u5b9e\u73b0\uff1a<\/p>\n
builder.Services.AddScoped<IPriceService, FrPriceService>();\nbuilder.Services.AddScoped<IPriceService, GbPriceService>();\nbuilder.Services.AddScoped<IPriceService, UsPriceService>();\nbuilder.Services.AddScoped<IPriceService, DefaultPriceService>();<\/code><\/pre>\n
\u5982\u679c\u8981\u5c06 IPriceService \u6ce8\u5165 PageModel \u6784\u9020\u51fd\u6570\uff0c\u5219\u59cb\u7ec8\u4f1a\u83b7\u5f97 DefaultPriceService\uff0c\u5982\u4e0a\u6240\u793a\uff0c\u56e0\u4e3a\u5b83\u662f\u6700\u540e\u4e00\u4e2a\u6ce8\u518c\u7684\u3002\u4f46\u662f\uff0c\u60a8\u4e5f\u53ef\u4ee5\u6ce8\u5165 IEnumerable\uff0c\u5b83\u5c06\u89e3\u6790\u4e3a\u6240\u6709\u5df2\u6ce8\u518c\u5b9e\u73b0\u7684\u96c6\u5408\u3002\u7136\u540e\uff0c\u53ea\u9700\u9009\u62e9\u9002\u7528\u4e8e\u5f53\u524d\u8bf7\u6c42\u7684\u5b9e\u73b0\u5373\u53ef\u3002<\/p>\n
\u6211\u662f Cloudflare \uff08https:\/\/www.cloudflare.com\/<\/a>\uff09 \u7684\u7c89\u4e1d\uff0c\u5b83\u63d0\u4f9b\u4e00\u7cfb\u5217\u4e0e Web \u76f8\u5173\u7684\u670d\u52a1\uff0c\u5305\u62ec\u5730\u7406\u5b9a\u4f4d\uff08\u53ef\u4ee5\u4f7f\u7528\u5176\u4ed6\u5730\u7406\u5b9a\u4f4d\u670d\u52a1\u63d0\u4f9b\u5546\uff09\uff0c\u4ece\u800c\u6839\u636e\u8bf7\u6c42\u7684 IP \u5730\u5740\u8bc6\u522b\u8bf7\u6c42\u7684\u4f4d\u7f6e\u3002\u8be5\u4f4d\u7f6e\u5728\u8bf7\u6c42\u6807\u5934\u4e2d\u4f5c\u4e3a ISO-3166-1 Alpha-2 \u4ee3\u7801\u6216\u201cXX\u201d\uff08\u65e0\u6cd5\u89e3\u6790\u8be5\u4f4d\u7f6e\uff09\u63d0\u4f9b\u7ed9\u5e94\u7528\u7a0b\u5e8f\u4ee3\u7801\u3002\u4e0b\u9762\u7684\u6e05\u5355\u663e\u793a\u4e86\u5982\u4f55\u4f7f\u7528\u6b64\u6807\u5934\u503c\u6839\u636e\u5f53\u524d\u8bf7\u6c42\u89e3\u6790\u8981\u8c03\u7528\u7684\u6b63\u786e\u670d\u52a1\u7684\u793a\u4f8b\u3002<\/p>\n
\u6e05\u5355 7.14 \u4ece\u591a\u4e2a\u5df2\u6ce8\u518c\u7684\u670d\u52a1\u4e2d\u89e3\u6790\u4e00\u4e2a<\/p>\n
public class CityModel : PageModel\n{\n    private readonly IEnumerable<IPriceService> _priceServices;\n    public CityModel(IEnumerable<IPriceService> priceServices)     \u2776\n    {\n        _priceServices = priceServices;\n    }\n\n    public void OnGet()\n    {\n        var locationCode = Request.Headers["CF-IPCountry"];        \u2777\n        var priceService = _priceServices.FirstOrDefault(s=> s.GetLocation()  \n        \u27a5 == locationCode);                                       \u2778\n        \/\/ do something with priceService\n    }\n}<\/code><\/pre>\n
\u2776 \u6ce8\u5165\u4e00\u4e2a\u8868\u793a\u6240\u6709\u5df2\u6ce8\u518c\u5b9e\u73b0\u7684\u96c6\u5408\u3002
\n\u2777 \u83b7\u53d6\u7528\u4e8e\u5b9a\u4e49\u9002\u7528\u4e8e\u6b64\u8bf7\u6c42\u7684\u5b9e\u73b0\u7684\u8fd0\u884c\u65f6\u6570\u636e\u3002
\n\u2778 \u67e5\u8be2\u4e0e\u4f20\u5165 FirstOrDefault \u65b9\u6cd5\u7684\u8c13\u8bcd\u5339\u914d\u7684\u670d\u52a1\u7684\u96c6\u5408\u3002<\/p>\n
\u91c7\u7528\u6b64\u6a21\u5f0f\u6709\u4e24\u4e2a\u660e\u663e\u7684\u597d\u5904\u3002\u9996\u5148\uff0c\u6bcf\u4e2a IPriceService \u5b9e\u73b0\u90fd\u662f\u7279\u5b9a\u4e8e\u4f4d\u7f6e\u7684\uff0c\u8fd9\u51cf\u5c11\u4e86\u5b83\u4eec\u6240\u9700\u7684\u4ee3\u7801\u91cf\uff0c\u4ece\u800c\u7b80\u5316\u4e86\u7ef4\u62a4\u4f53\u9a8c\u3002\u7b2c\u4e8c\u4e2a\u662f\uff0c\u5982\u679c\u60a8\u60f3\u8fce\u5408\u66f4\u591a\u4f4d\u7f6e\uff0c\u60a8\u53ea\u9700\u521b\u5efa\u4e00\u4e2a\u65b0\u670d\u52a1\u5e76\u5c06\u5176\u4e0e\u5176\u4ed6\u670d\u52a1\u4e00\u8d77\u6ce8\u518c\u3002\u5b83\u5c06\u81ea\u52a8\u89e3\u6790\u4e3a\u6ce8\u5165\u7684\u96c6\u5408\u7684\u4e00\u90e8\u5206\u3002<\/p>\n
\u8fd8\u6709\u53e6\u4e00\u79cd\u6ce8\u518c\u670d\u52a1\u7684\u65b9\u6cd5\uff0c\u5728\u6ce8\u518c\u4e86\u591a\u4e2a implementations \u7684\u60c5\u51b5\u4e0b\uff0c\u5c06\u5bfc\u81f4\u7b2c\u4e00\u4e2a registration \u5f97\u5230\u89e3\u51b3\uff0c\u800c\u4e0d\u662f\u6700\u540e\u4e00\u4e2a implementation\u3002\u5373\u4f7f\u7528 TryAdd<LIFETIME><\/code> \u65b9\u6cd5\u3002\u5982\u679c\u4f7f\u7528 TryAddScoped \u91cd\u590d\u6ce8\u518c IPriceService \u5b9e\u73b0\uff08\u5982\u4e0b\u9762\u7684\u6e05\u5355\u6240\u793a\uff09\uff0c\u5219\u5c06\u89e3\u6790\u7b2c\u4e00\u4e2a\u5b9e\u73b0\uff0c\u9664\u975e\u6ce8\u5165 IEnumerable\u3002<\/p>\n
\u5217\u8868 7.15 TryAdd<LIFETIME><\/code>\u5bfc\u81f4\u7b2c\u4e00\u4e2a\u5b9e\u73b0\u88ab\u89e3\u6790<\/p>\n
builder.Services.TryAddScoped<IPriceService, FrPriceService>();    \u2776\nbuilder.Services.TryAddScoped<IPriceService, GbPriceService>();\nbuilder.Services.TryAddScoped<IPriceService, UsPriceService>();\nbuilder.Services.TryAddScoped<IPriceService, DefaultPriceService>();<\/code><\/pre>\n
\u2776 \u89e3\u6790\u9996\u5148\u6ce8\u518c\u7684 implementation\u3002<\/p>\n
\u90a3\u4e48\uff0c\u4f55\u65f6\u4f7f\u7528 TryAdd \u65b9\u6cd5\u6ce8\u518c\u670d\u52a1\u5462\uff1f\u901a\u5e38\uff0c\u5982\u679c\u8981\u786e\u4fdd\u9ed8\u8ba4\u60c5\u51b5\u4e0b\u4e0d\u4f7f\u7528\u610f\u5916\u8fdb\u884c\u7684\u5176\u4ed6\u6ce8\u518c\uff0c\u5219\u53ef\u4ee5\u4f7f\u7528\u6b64\u65b9\u6cd5\u3002\u5982\u679c\u4e0d\u6e05\u695a\u6b63\u5728\u8fdb\u884c\u54ea\u4e9b\u6ce8\u518c\uff0c\u5219\u53ef\u80fd\u4f1a\u53d1\u751f\u8fd9\u79cd\u60c5\u51b5\uff0c\u56e0\u4e3a\u5b83\u4eec\u9690\u85cf\u5728\u6269\u5c55\u65b9\u6cd5\uff08\u4f8b\u5982 AddRazorPages \u65b9\u6cd5\uff09\u4e2d\u3002\u5e93\u4f5c\u8005\u53ef\u80fd\u5e0c\u671b\u786e\u4fdd\u4ed6\u4eec\u7684\u6ce8\u518c\u88ab\u4f7f\u7528\uff0c\u800c\u4e0d\u7ba1\u6846\u67b6\u7684\u4f7f\u7528\u8005\u968f\u540e\u5c1d\u8bd5\u505a\u4ec0\u4e48\u3002<\/p>\n
7.3 \u8bbf\u95ee\u5df2\u6ce8\u518c\u670d\u52a1\u7684\u5176\u4ed6\u65b9\u5f0f<\/h2>\n
\u6784\u9020\u51fd\u6570\u6ce8\u5165\u53ef\u80fd\u662f\u4f7f\u7528\u5df2\u6ce8\u518c\u670d\u52a1\u7684\u6700\u5e38\u89c1\u65b9\u5f0f\u3002\u4f46\u662f\uff0c\u60a8\u5e94\u8be5\u6ce8\u610f\u5176\u4ed6\u8bbf\u95ee\u670d\u52a1\u7684\u65b9\u6cd5\u3002\u60a8\u53ef\u80fd\u4f1a\u5728\u67d0\u4e2a\u9636\u6bb5\u4f7f\u7528\u5176\u4e2d\u4e00\u4e9b\u9009\u9879\uff0c\u4f46\u5b83\u4eec\u6709\u5176\u6ce8\u610f\u4e8b\u9879\u3002\u8fd9\u4e9b\u9009\u9879\u5305\u62ec\u76f4\u63a5\u6ce8\u5165 Razor \u6587\u4ef6\u3001\u65b9\u6cd5\u6ce8\u5165\u548c\u76f4\u63a5\u4ece\u670d\u52a1\u5bb9\u5668\u68c0\u7d22\u670d\u52a1\u3002<\/p>\n
7.3.1 \u89c6\u56fe\u6ce8\u5165<\/h3>\n
\u6846\u67b6\u63d0\u4f9b\u7684\u4e00\u4e9b\u670d\u52a1\u65e8\u5728\u5e2e\u52a9\u751f\u6210 HTML\u3002\u4e00\u4e2a\u793a\u4f8b\u662f IHtmlLocalizer \u670d\u52a1\uff0c\u8be5\u670d\u52a1\u7528\u4e8e\u5728\u9700\u8981\u5904\u7406\u591a\u79cd\u8bed\u8a00\u7684 Web \u5e94\u7528\u7a0b\u5e8f\u4e2d\u672c\u5730\u5316 HTML \u4ee3\u7801\u6bb5\u3002\u5b83\u5728 Razor \u9875\u9762\u6216\u89c6\u56fe\u4e4b\u5916\u6ca1\u6709\u4efb\u4f55\u7528\u9014\u3002\u53ef\u4ee5\u5c06\u6b64\u670d\u52a1\u6ce8\u5165\u5230\u9700\u8981\u5b83\u7684\u9875\u9762\u7684 PageModel \u4e2d\uff0c\u7136\u540e\u5c06\u5176\u5206\u914d\u7ed9\u516c\u5171\u5c5e\u6027\uff0c\u4ee5\u4fbf\u53ef\u4ee5\u901a\u8fc7 Razor \u9875\u9762\u672c\u8eab\u4e2d\u7684 Model \u8bbf\u95ee\u5b83\u3002\u4f46\u66f4\u597d\u7684\u89e3\u51b3\u65b9\u6848\u662f\u7b80\u5355\u5730\u4f7f\u7528 @inject \u6307\u4ee4\u5c06\u670d\u52a1\u76f4\u63a5\u6ce8\u5165\u9875\u9762\u3002<\/p>\n
\u6e05\u5355 7.16 \u4f7f\u7528 @inject \u6307\u4ee4\u5c06\u670d\u52a1\u6ce8\u5165 Razor \u9875\u9762<\/p>\n
@page\n@inject IHtmlLocalizer<IndexModel> htmlLocalizer  \u2776\n@model IndexModel\n@{\n    ViewData["Title"] = "Home page";\n}\n\n<div class="text-center">\n    <h1>Welcome<\/h1>\n    <p>@htmlLocalizer["Intro"]<\/p>                \u2777\n<\/div><\/code><\/pre>\n
\u2776 IHtmlLocalizer<T><\/code> \u670d\u52a1\u4f7f\u7528 @inject \u6307\u4ee4\u6ce8\u5165\uff0c\u5e76\u5206\u914d\u7ed9\u53d8\u91cf htmlLocalizer\u3002
\n\u2777 \u672c\u5730\u5316\u5de5\u5177\u670d\u52a1\u7528\u4e8e\u672c\u5730\u5316\u6807\u8bc6\u4e3a\u201cIntro\u201d\u7684 HTML \u7247\u6bb5\u3002<\/p>\n
\u6211\u5e94\u8be5\u5f3a\u8c03\u7684\u662f\uff0c\u5f53\u60a8\u4ec5\u5c06\u6b64\u65b9\u6cd5\u7528\u4e8e\u57fa\u4e8e HTML \u7684\u670d\u52a1\u65f6\uff0c\u6b64\u65b9\u6cd5\u5f88\u597d\u3002\u60a8\u4e0d\u5e94\u5c06\u4efb\u4f55\u5305\u542b\u4e1a\u52a1\u903b\u8f91\u7684\u670d\u52a1\u76f4\u63a5\u6ce8\u5165\u5230\u9875\u9762\u4e2d\u3002\u6211\u4eec\u7684\u4e1a\u52a1\u903b\u8f91\u8fdc\u79bb HTML\uff0c\u4e0d\u662f\u5417\uff1f<\/p>\n
7.3.2 \u65b9\u6cd5\u6ce8\u5165<\/h3>\n
\u5f00\u7bb1\u5373\u7528\uff0c\u9ed8\u8ba4\u670d\u52a1\u5bb9\u5668\u4ec5\u652f\u6301\u6784\u9020\u51fd\u6570\u6ce8\u5165\u3002\u4f46\u662f\uff0cASP.NET Core \u5728\u51e0\u4e2a\u5730\u65b9\u6dfb\u52a0\u4e86\u65b9\u6cd5\u53c2\u6570\u6ce8\u5165\u3002\u60a8\u5df2\u7ecf\u5728\u7b2c 2 \u7ae0\u4e2d\u770b\u5230\u8fc7\u4e00\u4e2a\u4f8b\u5b50\uff0c\u5f53\u65f6\u6211\u4eec\u7814\u7a76\u4e86\u5982\u4f55\u521b\u5efa\u4f20\u7edf\u7684\u4e2d\u95f4\u4ef6\u3002\u5982\u679c\u60a8\u8fd8\u8bb0\u5f97\uff0c\u60a8\u5df2\u5c06 ILogger<T><\/code> \u6ce8\u5165\u5230 InvokeAsync \u65b9\u6cd5\u4e2d\uff1a<\/p>\n
public async Task InvokeAsync(HttpContext context, \n\u27a5 ILogger<IpAddressMiddleware> logger)<\/code><\/pre>\n
\u4f46\u662f\u5904\u7406\u7a0b\u5e8f\u65b9\u6cd5\u5462\uff1f\u6bd5\u7adf\uff0c\u5904\u7406\u7a0b\u5e8f\u65b9\u6cd5\u53c2\u6570\u88ab\u6a21\u578b Binder \u89c6\u4e3a\u7ed1\u5b9a\u76ee\u6807\u3002\u5f53\u6a21\u578b\u7ed1\u5b9a\u5668\u9047\u5230 IPriceService \u53c2\u6570\u65f6\u4f1a\u53d1\u751f\u4ec0\u4e48\u60c5\u51b5\uff1f\u60a8\u7684\u5e94\u7528\u7a0b\u5e8f\u4e2d\u65ad\u3002\u9664\u975e\u5728 service \u53c2\u6570\u524d\u9762\u52a0\u4e0a FromServices \u5c5e\u6027\uff0c\u5426\u5219\u5c31\u4f1a\u53d1\u751f\u8fd9\u79cd\u60c5\u51b5\uff1a<\/p>\n
public async Task OnGetAsync([FromServices]IPriceService service)\n{\n    \/\/ do something with service\n}<\/code><\/pre>\n
\u5bf9\u4e8e\u521b\u5efa\u6210\u672c\u9ad8\u6602\u4f46\u5728 Razor \u9875\u9762\u4e2d\u4ec5\u4f7f\u7528\u4e00\u5c0f\u90e8\u5206\u65f6\u95f4\u7684\u670d\u52a1\uff0c\u8fd9\u662f\u4e00\u79cd\u6709\u7528\u7684\u6a21\u5f0f\u3002\u4f8b\u5982\uff0c\u9875\u9762\u4e2d\u6709\u4e00\u4e2a\u547d\u540d\u5904\u7406\u7a0b\u5e8f\uff0c\u8be5\u5904\u7406\u7a0b\u5e8f\u9700\u8981 OnGet \u548c OnPost \u5904\u7406\u7a0b\u5e8f\u4e0d\u9700\u8981\u7684\u670d\u52a1\uff0c\u5e76\u4e14\u4ec5\u5728\u67d0\u4e9b\u60c5\u51b5\u4e0b\u8c03\u7528\u547d\u540d\u5904\u7406\u7a0b\u5e8f\u3002\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0c\u5c06\u670d\u52a1\u6ce8\u5165 PageModel \u6784\u9020\u51fd\u6570\u51e0\u4e4e\u6ca1\u6709\u610f\u4e49\u3002FromServices \u5c5e\u6027\u5141\u8bb8\u60a8\u5c06\u670d\u52a1\u8303\u56f4\u9650\u5b9a\u4e3a\u9700\u8981\u5b83\u7684\u5904\u7406\u7a0b\u5e8f\u65b9\u6cd5\uff0c\u5e76\u4e14\u4ec5\u5728\u9700\u8981\u65f6\u89e3\u6790\u5b83\u3002<\/p>\n
7.3.3 \u4f7f\u7528 GetService \u548c GetRequiredService \u76f4\u63a5\u4ece\u670d\u52a1\u5bb9\u5668<\/h3>\n
\u6709\u65f6\uff0c\u60a8\u9700\u8981\u76f4\u63a5\u8bbf\u95ee\u670d\u52a1\u7684\u670d\u52a1\u5bb9\u5668\u3002\u8fd9\u79cd\u65b9\u6cd5\u79f0\u4e3a Service Locator \u6a21\u5f0f\u3002\u8fd9\u542c\u8d77\u6765\u50cf\u662f\u4e00\u4ef6\u597d\u4e8b\uff0c\u4f5c\u4e3a\u4e00\u79cd\u8bbe\u8ba1\u6a21\u5f0f\u7b49\u7b49\uff0c\u4f46\u5b83\u901a\u5e38\u88ab\u8ba4\u4e3a\u662f\u4e00\u79cd\u53cd\u6a21\u5f0f\uff0c\u5e94\u8be5\u907f\u514d\u3002\u4f46\u662f\uff0c\u6709\u65f6\u60a8\u522b\u65e0\u9009\u62e9\u3002\u5728\u672c\u7ae0\u524d\u9762\uff0c\u5f53\u60a8\u4f7f\u7528\u5de5\u5382\u6ce8\u518c\u4e00\u4e2a\u670d\u52a1\u65f6\uff0c\u60a8\u5df2\u7ecf\u770b\u5230\u4e86\u8fd9\u6837\u4e00\u4e2a\u4f8b\u5b50\uff0c\u8be5\u670d\u52a1\u5c06\u53e6\u4e00\u4e2a\u670d\u52a1\u4f5c\u4e3a\u4f9d\u8d56\u9879\u3002<\/p>\n
\u5b9a\u4e49\u53cd\u6a21\u5f0f\u662f\u9488\u5bf9\u53cd\u590d\u51fa\u73b0\u7684\u95ee\u9898\uff08\u6a21\u5f0f\uff09\u7684\u5e38\u7528\u89e3\u51b3\u65b9\u6848\uff0c\u901a\u5e38\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u662f\u6b21\u4f18\u7684\u3002\u8fd9\u53ef\u80fd\u662f\u56e0\u4e3a\u8be5\u89e3\u51b3\u65b9\u6848\u5f15\u5165\u4e86\u65b0\u95ee\u9898\uff0c\u6216\u8005\u56e0\u4e3a\u5b83\u53ea\u662f\u5c06\u95ee\u9898\u8f6c\u79fb\u5230\u4e86\u5176\u4ed6\u4f4d\u7f6e\u3002<\/p>\n
IServiceProvider \u670d\u52a1\u63d0\u4f9b\u5bf9\u5df2\u6ce8\u518c\u670d\u52a1\u7684\u8bbf\u95ee\u3002\u5b83\u6709\u4e00\u4e2a\u65b9\u6cd5 GetService\uff0c\u8be5\u65b9\u6cd5\u8fd4\u56de\u6307\u5b9a\u7684\u670d\u52a1\uff0c\u5982\u679c\u672a\u627e\u5230\uff0c\u5219\u8fd4\u56de null\u3002\u6b64\u5916\uff0c\u8fd8\u6709\u4e00\u4e2a\u6269\u5c55\u65b9\u6cd5 GetRequiredService\uff0c\u5982\u679c\u672a\u627e\u5230\u6307\u5b9a\u7684\u670d\u52a1\uff0c\u5219\u4f1a\u5f15\u53d1\u5f02\u5e38\u3002\u5c06 IServiceProvider \u6ce8\u5165\u5230\u4f7f\u7528\u8005\u4e2d\uff0c\u7136\u540e\u4f7f\u7528\u8005\u4f7f\u7528\u5b83\u6765\u68c0\u7d22\u6240\u9700\u7684\u670d\u52a1\u3002<\/p>\n
\u6e05\u5355 7.17 \u670d\u52a1\u5b9a\u4f4d\u5668\u6a21\u5f0f\u7684\u793a\u4f8b\u7528\u6cd5<\/p>\n
public class IndexModel : PageModel\n{\n    private readonly IServiceProvider _serviceProvider;           \u2776\n\n    public IndexModel(IServiceProvider serviceProvider) =>] \n    \u27a5  _serviceProvider = serviceProvider;                       \u2776\n\n    public List<City> Cities { get; set; }                        \u2776\n    public async Task OnGetAsync()\n    {\n        var cityService = \n        \u27a5 _serviceProvider.GetRequiredService<ICityService>();   \u2776\n        Cities = await cityService.GetAllAsync();\n    }\n}<\/code><\/pre>\n
\u2776 \u5c06 IServiceProvider \u6ce8\u5165\u7c7b\u6784\u9020\u51fd\u6570\u3002<\/p>\n
\u56de\u60f3\u4e00\u4e0b\u6211\u6240\u8bf4\u7684\u663e\u5f0f\u4f9d\u8d56\u5173\u7cfb\u539f\u5219\uff0c\u60a8\u4e5f\u8bb8\u80fd\u591f\u8fa8\u522b\u4e3a\u4ec0\u4e48\u670d\u52a1\u5b9a\u4f4d\u5668\u662f\u4e00\u79cd\u53cd\u6a21\u5f0f\u3002\u4ece\u6e05\u5355 7.17 \u4e2d\u7684\u4ee3\u7801\u4e2d\u4e0d\u6e05\u695a IndexModel \u7684\u4f9d\u8d56\u9879\u662f\u4ec0\u4e48\u2014\u2014\u9664\u4e86\u670d\u52a1\u63d0\u4f9b\u5546\u4e4b\u5916\u3002\u4e8b\u5b9e\u4e0a\uff0c\u5b83\u4ecd\u7136\u4f9d\u8d56\u4e8e ICityService\uff0c\u4f46\u8be5\u8be6\u7ec6\u4fe1\u606f\u4e0d\u518d\u5bf9\u7c7b\u5916\u90e8\u7684\u4ee3\u7801\u53ef\u89c1\u3002<\/p>\n
\u670d\u52a1\u63d0\u4f9b\u8005\u4e5f\u4f5c\u4e3a\u8bf7\u6c42\u529f\u80fd \uff08http:\/\/mng.bz\/neE2<\/a>\uff09 \u63d0\u4f9b\uff0c\u56e0\u6b64\u60a8\u751a\u81f3\u4e0d\u9700\u8981\u5c06\u63d0\u4f9b\u8005\u6ce8\u5165\u53ef\u4ee5\u8bbf\u95ee HttpContext \u7684\u7c7b\u4e2d\u3002\u60a8\u53ef\u4ee5\u5c06\u89e3\u6790\u6e05\u5355 7.17 \u4e2d city \u670d\u52a1\u7684\u4ee3\u7801\u884c\u66ff\u6362\u4e3a\u4ee5\u4e0b\u5185\u5bb9\uff1a<\/p>\n
var cityService = \n\u27a5 HttpContext.RequestServices.GetRequiredService<ICityService>();<\/code><\/pre>\n
\u4f9d\u8d56\u9879\u6ce8\u5165\u548c\u968f\u4e4b\u800c\u6765\u7684\u5176\u4ed6\u672f\u8bed\u542c\u8d77\u6765\u5f88\u590d\u6742\uff0c\u4f46\u73b0\u5b9e\u60c5\u51b5\u662f\uff0c\u5b83\u662f\u4e00\u79cd\u975e\u5e38\u7b80\u5355\u7684\u6280\u672f\uff0c\u6709\u52a9\u4e8e\u5b9e\u73b0\u9ad8\u8d28\u91cf\u7684\u4ee3\u7801\u3002\u5185\u7f6e\u670d\u52a1\u5bb9\u5668\u5e94\u8be5\u8db3\u4ee5\u6ee1\u8db3\u5927\u591a\u6570\u4f7f\u7528\u6848\u4f8b\uff0c\u4f46\u5982\u679c\u60a8\u53d1\u73b0\u81ea\u5df1\u9700\u8981\u66f4\u9ad8\u7ea7\u7684\u4e1c\u897f\uff0c\u60a8\u53ef\u4ee5\u4f7f\u7528\u652f\u6301 ASP.NET Core \u7684\u4f17\u591a\uff08\u901a\u5e38\u662f\u514d\u8d39\u548c\u5f00\u6e90\u7684\uff09\u7b2c\u4e09\u65b9\u5bb9\u5668\u4e4b\u4e00\u3002\u96c6\u6210\u901a\u5e38\u975e\u5e38\u7b80\u5355\uff0c\u4f9b\u5e94\u5546\u5e94\u5b8c\u6574\u8bb0\u5f55\u3002<\/p>\n
\u5728\u4e0b\u4e00\u7ae0\u4e2d\uff0c\u6211\u4eec\u5c06\u4e86\u89e3\u5982\u4f55\u5728 Razor Pages \u5e94\u7528\u7a0b\u5e8f\u4e2d\u5904\u7406\u6570\u636e\u3002\u5728\u6b64\u8fc7\u7a0b\u4e2d\uff0c\u6211\u4eec\u5c06\u521b\u5efa\u4e00\u4e2a\u65b0\u670d\u52a1\uff0c\u4ece\u6570\u636e\u5e93\u4e2d\u83b7\u53d6\u6570\u636e\uff0c\u5e76\u5c06\u73b0\u6709\u670d\u52a1\u65e0\u7f1d\u5730\u66ff\u6362\u4e3a\u65b0\u670d\u52a1\uff0c\u8fd9\u5c55\u793a\u4e86 using DI \u7684\u4e3b\u8981\u4f18\u52bf\u4e4b\u4e00\u3002<\/p>\n
\u603b\u7ed3<\/h2>\n
\u4f9d\u8d56\u9879\u6ce8\u5165 \uff08DI\uff09 \u662f ASP.NET Core \u4e2d\u7684\u4e00\u9879\u5173\u952e\u529f\u80fd\u3002
\nDI \u53ef\u5e2e\u52a9\u60a8\u5b9e\u73b0\u63a7\u5236\u53cd\u8f6c\uff0c\u8fd9\u662f\u4e00\u79cd\u4fc3\u8fdb\u4ee3\u7801\u677e\u6563\u8026\u5408\u7684\u6280\u672f\u3002
\n\u670d\u52a1\u88ab\u6ce8\u5165\u5230\u4f9d\u8d56\u4e8e\u5b83\u4eec\u7684\u7c7b\u4e2d\uff0c\u8fd9\u4e9b\u7c7b\u4f5c\u4e3a\u663e\u5f0f\u4f9d\u8d56\u9879\u3002
\n\u4f9d\u8d56\u5173\u7cfb\u53cd\u8f6c\u539f\u5219 \uff08DIP\uff09 \u6307\u51fa\uff0c\u9ad8\u7ea7\u7c7b\u548c\u4f4e\u7ea7\u7c7b\u5e94\u4f9d\u8d56\u4e8e\u62bd\u8c61\uff0c\u4f8b\u5982\u63a5\u53e3\u3002
\n\u60a8\u53ef\u4ee5\u901a\u8fc7 WebApplication Services \u5c5e\u6027\u5728 Program.cs \u4e2d\u914d\u7f6e\u670d\u52a1\uff0c\u8be5\u5c5e\u6027\u8868\u793a\u4e3a\u5e94\u7528\u7a0b\u5e8f\u914d\u7f6e\u7684\u670d\u52a1\u3002
\n\u670d\u52a1\u6ce8\u518c\u4e3a\u670d\u52a1\u5bb9\u5668\u7684\u7c7b\u578b\u548c\u5b9e\u73b0\u3002
\n\u670d\u52a1\u4f7f\u7528\u4ee5\u4e0b\u4e09\u4e2a\u751f\u5b58\u671f\u4e4b\u4e00\u8fdb\u884c\u6ce8\u518c\uff1a\u5355\u4e00\u5b9e\u4f8b\u3001\u77ac\u6001\u6216\u4f5c\u7528\u57df\u3002
\n\u53ea\u80fd\u5b58\u5728\u4e00\u4e2a\u5355\u4e00\u5b9e\u4f8b\u7684\u5b9e\u4f8b\u3002\u5b83\u5728\u5bb9\u5668\u7684\u751f\u547d\u5468\u671f\u5185\u6301\u7eed\u3002
\n\u6bcf\u6b21\u8bf7\u6c42\u4e34\u65f6\u670d\u52a1\u65f6\uff0c\u90fd\u4f1a\u5bf9\u5176\u8fdb\u884c\u89e3\u6790\u3002
\n\u5206\u533a\u670d\u52a1\u5728 ASP.NET Core \u4e2d Web \u8bf7\u6c42\u7684\u6301\u7eed\u65f6\u95f4\u5185\u6301\u7eed\u3002
\n\u53ef\u4ee5\u6ce8\u518c\u540c\u4e00\u670d\u52a1\u7684\u591a\u4e2a\u5b9e\u73b0\u3002\u6700\u540e\u4e00\u4e2a\u6ce8\u518c\u7684\u95ee\u9898\u5c06\u88ab\u89e3\u6790\u3002
\n\u60a8\u53ef\u4ee5\u901a\u8fc7\u6ce8\u5165\u548c IEnumerable <ServiceType><\/code> \u8bbf\u95ee\u6240\u6709\u5df2\u6ce8\u518c\u7684\u5b9e\u73b0\u3002
\n\u60a8\u53ef\u4ee5\u901a\u8fc7\u5728 service \u53c2\u6570\u524d\u9762\u52a0\u4e0a [FromServices] \u6765\u6ce8\u5165\u5230\u9875\u9762\u5904\u7406\u7a0b\u5e8f\u65b9\u6cd5\u4e2d\u3002
\n\u60a8\u53ef\u4ee5\u901a\u8fc7 @inject \u5c5e\u6027\u76f4\u63a5\u6ce8\u5165 Razor \u9875\u9762\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
ASP.NET Core Razor Pages in Action 7 \u4f7f\u7528\u4f9d\u8d56\u5173\u7cfb\u6ce8\u5165\u7ba1\u7406\u670d\u52a1 \u672c\u7ae0\u6db5\u76d6 \u2022 \u4e86\u89e3\u4f9d\u8d56\u5173\u7cfb\u6ce8\u5165\u7684\u4f5c\u7528 \u2022 \u68c0\u67e5 ASP.NET Core \u4e2d\u7684\u4f9d\u8d56\u9879\u6ce8\u5165 \u2022 \u521b\u5efa\u548c\u4f7f\u7528\u60a8\u81ea\u5df1\u7684\u670d\u52a1 \u2022 \u7ba1\u7406\u670d\u52a1\u751f\u547d\u5468\u671f \u4f9d\u8d56\u6ce8\u5165 \uff08DI\uff09 \u662f\u4e00\u79cd\u8f6f\u4ef6\u5de5\u7a0b\u6280\u672f\uff0c\u76ee\u524d\u8bb8\u591a Web \u6846\u67b6\u90fd\u5305\u542b\u5728\u5185\u3002\u5b83\u5b58\u5728\u7684\u7406\u7531\u662f\u5b9e\u73b0\u8f6f\u4ef6\u7ec4\u4ef6\u4e4b\u95f4\u7684\u677e\u6563\u8026\u5408\uff0c\u4ece\u800c\u4f7f\u4ee3\u7801\u4e0d\u90a3\u4e48\u8106\u5f31\u3001\u66f4\u9002\u5e94\u53d8\u5316\u3001\u66f4\u6613\u4e8e\u7ef4\u62a4\u548c\u66f4\u6613\u4e8e\u6d4b\u8bd5\u3002\u5982\u679c\u60a8\u4ee5\u524d\u4f7f\u7528\u8fc7\u4f9d\u8d56\u6ce8\u5165\uff0c\u90a3\u4e48\u6240\u6709\u8fd9\u4e9b\u5bf9\u60a8\u6765\u8bf4\u90fd\u4f1a\u5f88\u719f\u6089\u3002\u5982\u679c\u4f9d\u8d56\u6ce8\u5165\u5bf9\u4f60\u6765\u8bf4\u662f\u4e00\u4e2a\u65b0\u6982\u5ff5\uff0c\u672c\u7ae0\u5c06\u901a\u8fc7\u89e3\u91ca\u5b83\u662f\u4ec0\u4e48\u4ee5\u53ca\u4e3a\u4ec0\u4e48\u4f60\u5e94\u8be5\u5173\u5fc3\u6765\u63d0\u4f9b\u5e2e\u52a9\u3002 DI \u662f ASP.NET Core \u7684\u6838\u5fc3\u3002\u6574\u4e2a\u6846\u67b6\u4f7f\u7528\u5185\u7f6e\u7684 DI \u529f\u80fd\u6765\u7ba1\u7406\u81ea\u5df1\u7684\u4f9d\u8d56\u9879\u6216\u670d\u52a1\u3002\u5f53\u5e94\u7528\u7a0b\u5e8f\u542f\u52a8\u65f6\uff0c\u670d\u52a1\u5728\u5bb9\u5668\u4e2d\u5168\u5c40\u6ce8\u518c\uff0c\u7136\u540e\u5728\u4f7f\u7528\u8005\u9700\u8981\u65f6\u7531\u5bb9\u5668\u63d0\u4f9b\u3002\u5728\u7b2c 2 \u7ae0\u4e2d\uff0c\u60a8\u9047\u5230\u4e86\u670d\u52a1\u5bb9\u5668\u7684\u4e3b\u5165\u53e3\u70b9\uff0cProgram.cs\u5b83\u901a\u8fc7 WebApplicationBuilder \u7684 Services \u5c5e\u6027\u8fdb\u884c\u8bbf\u95ee\u3002\u60a8\u4f1a\u8bb0\u5f97\uff0c\u7ec4\u6210 Razor Pages \u6846\u67b6\u7684\u670d\u52a1\u662f\u901a\u8fc7 AddRazorPages \u65b9\u6cd5\u6ce8\u518c\u5230\u5bb9\u5668\u4e2d\u7684\uff1a var builder = WebApplication.CreateBuilder(args); \/\/ Add services to the container. builder.Services.AddRazorPages(); \u9664\u4e86\u6846\u67b6\u4f7f\u7528\u5176\u5bb9\u5668\u4e4b\u5916\uff0c\u8fd8\u9f13\u52b1\u60a8\u4f7f\u7528\u5b83\u6765\u6ce8\u518c\u81ea\u5df1\u7684\u670d\u52a1\uff0c\u4ee5\u4fbf\u5bb9\u5668\u53ef\u4ee5\u5c06\u5b83\u4eec\u6ce8\u5165\u5230\u4f7f\u7528\u8005\u4e2d\uff0c\u5bb9\u5668\u5c06\u8d1f\u8d23\u4ee3\u8868\u60a8\u7ba1\u7406\u8fd9\u4e9b\u670d\u52a1\u7684\u751f\u547d\u5468\u671f\uff08\u521b\u5efa\u548c\u9500\u6bc1\uff09\u3002\u8fd9\u91cc\u8981\u8bf4\u660e\u7684\u4e00\u4e2a\u5173\u952e\u70b9\u662f\uff0c\u60a8\u4e0d\u9700\u8981\u5c06 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-1069","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/diji.net\/index.php?rest_route=\/wp\/v2\/posts\/1069","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/diji.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/diji.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/diji.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/diji.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1069"}],"version-history":[{"count":0,"href":"https:\/\/diji.net\/index.php?rest_route=\/wp\/v2\/posts\/1069\/revisions"}],"wp:attachment":[{"href":"https:\/\/diji.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1069"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/diji.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1069"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/diji.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1069"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}