C#\u91cd\u6784\u4ee3\u7801\u76848\u79cd\u57fa\u672c\u65b9\u6cd5<\/p>\n
\u91cd\u6784\u662f\u6307\u5728\u4e0d\u6539\u53d8\u4ee3\u7801\u884c\u4e3a\u7684\u60c5\u51b5\u4e0b\uff0c\u63d0\u9ad8\u4ee3\u7801\u7684\u53ef\u8bfb\u6027\u3001\u53ef\u7ef4\u62a4\u6027\u548c\u6548\u7387\u7684\u8fc7\u7a0b\u3002\u672c\u6587\u4ecb\u7ecd8\u79cd\u91cd\u6784C#\u4ee3\u7801\u7684\u57fa\u672c\u65b9\u6cd5\u3002<\/p>\n
\u5220\u9664\u5197\u4f59\u4ee3\u7801
\n\u91cd\u6784\u524d<\/p>\n
List<int> userIds = new List<int>();\nuserIds.AddRange(output.Select(s => s.UserId).Distinct().ToList());\nuserIds = userIds.Distinct().ToList();<\/code><\/pre>\n\u91cd\u6784\u540e<\/p>\n
var userIds = output.Select(s => s.UserId).Distinct().ToList();<\/code><\/pre>\n<\/li>\n- \n
\u4f7f\u7528LINQ\u66ff\u4ee3\u5faa\u73af
\n\u91cd\u6784\u524d<\/p>\n
List<int> evenNumbers = new List<int>();\nforeach (var num in numbers) {\nif (num % 2 == 0) {\n evenNumbers.Add(num);\n}\n}<\/code><\/pre>\n\u91cd\u6784\u540e<\/p>\n
var evenNumbers = numbers.Where(n => n % 2 == 0).ToList();<\/code><\/pre>\n<\/li>\n- \n
\u907f\u514d\u91cd\u590d\u4ee3\u7801\uff08\u5c01\u88c5\u65b9\u6cd5\uff09
\n\u91cd\u6784\u524d<\/p>\n
var segmentIDs = output.Select(s => s.SegmentID).Distinct().ToList();\nif (segmentIDs.Any()) {\nsegments = db.CheckCode\n .Where(c => segmentIDs.Contains(c.CheckCodeID))\n .ToList();\n}<\/code><\/pre>\n\u91cd\u6784\u540e<\/p>\n
List<int> GetDistinctIDs<T>(IEnumerable<T> source, Func<T, int?> selector) =>\nsource.Select(selector).Where(id => id.HasValue).Select(id => id.Value).Distinct().ToList();<\/code><\/pre>\n<\/li>\n- \n
\u4f7f\u7528\u7a7a\u5408\u5e76\u548c\u4e09\u5143\u8fd0\u7b97\u7b26
\n\u91cd\u6784\u524d<\/p>\n
string name;\nif (user != null && user.Name != null) {\nname = user.Name;\n} else {\nname = "Unknown";\n}<\/code><\/pre>\n\u91cd\u6784\u540e<\/p>\n
string name = user?.Name ?? "Unknown";<\/code><\/pre>\n<\/li>\n- \n
\u4f7f\u7528var\u63d0\u5347\u53ef\u8bfb\u6027
\n\u91cd\u6784\u524d<\/p>\n
List<int> numbers = new List<int> { 1, 2, 3, 4 };<\/code><\/pre>\n\u91cd\u6784\u540e<\/p>\n
var numbers = new List<int> { 1, 2, 3, 4 };<\/code><\/pre>\n<\/li>\n- \n
\u907f\u514d\u5d4c\u5957\u7684if\u8bed\u53e5
\n\u91cd\u6784\u524d<\/p>\n
if (user != null) {\nif (user.Age > 18) {\n Console.WriteLine("Adult");\n}\n}<\/code><\/pre>\n\u91cd\u6784\u540e<\/p>\n
if (user == null) return;\nif (user.Age <= 18) return;\nConsole.WriteLine("Adult");<\/code><\/pre>\n<\/li>\n- \n
\u4f7f\u7528\u5b57\u7b26\u4e32\u63d2\u503c
\n\u91cd\u6784\u524d<\/p>\n
string message = string.Format("Hello, {0}! You have {1} messages.", name, count);<\/code><\/pre>\n\u91cd\u6784\u540e<\/p>\n
string message = $"Hello, {name}! You have {count} messages.";<\/code><\/pre>\n<\/li>\n- \n
\u4f7f\u7528async\/await\u63d0\u5347\u6027\u80fd
\n\u91cd\u6784\u524d<\/p>\n
public List<User> GetUsers() {\nreturn db.Users.ToList();\n}<\/code><\/pre>\n\u91cd\u6784\u540e<\/p>\n
public async Task<List<User>> GetUsersAsync() {\nreturn await db.Users.ToListAsync();\n}<\/code><\/pre>\n<\/li>\n<\/ol>\n\u603b\u7ed3
\n\u5728\u4ee3\u7801\u91cd\u6784\u65f6\uff0c\u5e94\u8be5\u59cb\u7ec8\u9075\u5faa\u4ee5\u4e0b\u539f\u5219\uff1a<\/p>\n
\u53ef\u8bfb\u6027\uff1a\u4ee3\u7801\u5e94\u5f53\u6613\u4e8e\u7406\u89e3\u3002
\n\u53ef\u7ef4\u62a4\u6027\uff1a\u8ba9\u672a\u6765\u7684\u5f00\u53d1\u8005\u80fd\u591f\u8f7b\u677e\u4fee\u6539\u4ee3\u7801\u3002
\n\u6027\u80fd\uff1a\u907f\u514d\u4e0d\u5fc5\u8981\u7684\u8ba1\u7b97\u548c\u5197\u4f59\u64cd\u4f5c\u3002
\nDRY\uff08\u4e0d\u8981\u91cd\u590d\u81ea\u5df1\uff09\uff1a\u63d0\u53d6\u53ef\u590d\u7528\u7684\u903b\u8f91\u5230\u65b9\u6cd5\u4e2d\uff0c\u63d0\u9ad8\u4ee3\u7801\u590d\u7528\u6027\u3002
\n\u8bd1\u6587\uff1acsharp.com\/article\/learn-c-sharp-refactor-code<\/p>\n