{"id":769,"date":"2024-07-21T23:40:16","date_gmt":"2024-07-22T06:40:16","guid":{"rendered":"https:\/\/devblogs.microsoft.com\/dotnet-ch\/?p=769"},"modified":"2024-07-21T23:40:16","modified_gmt":"2024-07-22T06:40:16","slug":"c12%e6%96%b0%e5%8a%9f%e8%83%bd%e5%90%88%e9%9b%86%e5%9b%9b%ef%bc%9a%e4%bd%bf%e7%94%a8%e9%bb%98%e8%ae%a4-lambda-%e5%8f%82%e6%95%b0%e9%87%8d%e6%9e%84c%e4%bb%a3%e7%a0%81","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/dotnet-ch\/c12%e6%96%b0%e5%8a%9f%e8%83%bd%e5%90%88%e9%9b%86%e5%9b%9b%ef%bc%9a%e4%bd%bf%e7%94%a8%e9%bb%98%e8%ae%a4-lambda-%e5%8f%82%e6%95%b0%e9%87%8d%e6%9e%84c%e4%bb%a3%e7%a0%81\/","title":{"rendered":"C#12\u65b0\u529f\u80fd\u5408\u96c6\u56db\uff1a\u4f7f\u7528\u9ed8\u8ba4 lambda \u53c2\u6570\u91cd\u6784C#\u4ee3\u7801"},"content":{"rendered":"<p><span style=\"font-size: 12pt;\"><em>\u672c\u6587\u7ffb\u8bd1\u4e8eDavid Pine\u7684\u8fd9\u7bc7\u6587\u7ae0:<a class=\"Hyperlink SCXW152195964 BCX8\" href=\"https:\/\/devblogs.microsoft.com\/dotnet\/refactor-your-code-with-default-lambda-parameters\/\" target=\"_blank\" rel=\"noreferrer noopener\"><span class=\"TextRun Underlined SCXW152195964 BCX8\" lang=\"EN-US\" xml:lang=\"EN-US\" data-contrast=\"none\"><span class=\"NormalTextRun SCXW152195964 BCX8\" data-ccp-charstyle=\"Hyperlink\">Refactor your code with default lambda parameters<\/span><\/span><\/a><span class=\"EOP SCXW152195964 BCX8\" data-ccp-props=\"{&quot;134245417&quot;:false,&quot;335551550&quot;:2,&quot;335551620&quot;:2}\">\u00a0\u3002<\/span><\/em><\/span><\/p>\n<p><span data-contrast=\"auto\">\u672c\u6587\u662f\u63a2\u8ba8<\/span><span data-contrast=\"auto\"> C# 12<\/span><span data-contrast=\"auto\">\u7684\u5404\u79cd\u529f\u80fd\u7684\u56db\u7bc7\u7cfb\u5217\u6587\u7ae0\u4e2d\u7684\u6700\u540e\u4e00\u7bc7\u3002\u5728\u8fd9\u7bc7\u6587\u7ae0\u4e2d\uff0c\u6211\u4eec\u5c06\u63a2\u8ba8\u201c\u9ed8\u8ba4<\/span><span data-contrast=\"auto\"> lambda <\/span><span data-contrast=\"auto\">\u53c2\u6570\u201d\u529f\u80fd\uff0c\u4f7f\u5f00\u53d1\u4eba\u5458\u80fd\u591f\u5728<\/span><span data-contrast=\"auto\"> lambda <\/span><span data-contrast=\"auto\">\u8868\u8fbe\u5f0f\u4e2d\u4f7f\u7528\u9ed8\u8ba4\u53c2\u6570\u503c\u3002\u672c\u7cfb\u5217\u6db5\u76d6\u4e86\u5f88\u591a\u5185\u5bb9<\/span><span data-contrast=\"auto\">\uff1a<\/span><span data-ccp-props=\"{&quot;134245417&quot;:false,&quot;335551550&quot;:6,&quot;335551620&quot;:6}\">\u00a0<\/span><\/p>\n<ul>\n<li data-leveltext=\"%1.\" data-font=\"\" data-listid=\"1\" data-list-defn-props=\"{&quot;335552541&quot;:0,&quot;335559685&quot;:860,&quot;335559991&quot;:440,&quot;469769242&quot;:[65533,0],&quot;469777803&quot;:&quot;left&quot;,&quot;469777804&quot;:&quot;%1.&quot;,&quot;469777815&quot;:&quot;hybridMultilevel&quot;}\" aria-setsize=\"-1\" data-aria-posinset=\"1\" data-aria-level=\"1\"><a href=\"https:\/\/devblogs.microsoft.com\/dotnet-ch\/c12%e6%96%b0%e5%8a%9f%e8%83%bd%e5%90%88%e9%9b%86%e4%ba%8c%ef%bc%9a%e4%bd%bf%e7%94%a8%e9%9b%86%e5%90%88%e8%a1%a8%e8%be%be%e5%bc%8f%e9%87%8d%e6%9e%84%e4%bb%a3%e7%a0%81\/\"><span data-contrast=\"auto\">\u4f7f\u7528\u4e3b\u6784\u9020\u51fd\u6570\u91cd\u6784<\/span><span data-contrast=\"auto\"> C# <\/span><span data-contrast=\"none\">\u4ee3\u7801<\/span><\/a><span data-ccp-props=\"{&quot;134245417&quot;:false,&quot;335551550&quot;:6,&quot;335551620&quot;:6}\">\u00a0<\/span><\/li>\n<\/ul>\n<ul>\n<li data-leveltext=\"%1.\" data-font=\"\" data-listid=\"1\" data-list-defn-props=\"{&quot;335552541&quot;:0,&quot;335559685&quot;:860,&quot;335559991&quot;:440,&quot;469769242&quot;:[65533,0],&quot;469777803&quot;:&quot;left&quot;,&quot;469777804&quot;:&quot;%1.&quot;,&quot;469777815&quot;:&quot;hybridMultilevel&quot;}\" aria-setsize=\"-1\" data-aria-posinset=\"2\" data-aria-level=\"1\"><a href=\"https:\/\/devblogs.microsoft.com\/dotnet-ch\/c12%e6%96%b0%e5%8a%9f%e8%83%bd%e5%90%88%e9%9b%86%e4%ba%8c%ef%bc%9a%e4%bd%bf%e7%94%a8%e9%9b%86%e5%90%88%e8%a1%a8%e8%be%be%e5%bc%8f%e9%87%8d%e6%9e%84%e4%bb%a3%e7%a0%81\/\"><span data-contrast=\"auto\">\u4f7f\u7528\u96c6\u5408\u8868\u8fbe\u5f0f\u91cd\u6784<\/span><span data-contrast=\"auto\"> C# <\/span><span data-contrast=\"none\">\u4ee3\u7801<\/span><\/a><span data-ccp-props=\"{&quot;134245417&quot;:false,&quot;335551550&quot;:6,&quot;335551620&quot;:6}\">\u00a0<\/span><\/li>\n<\/ul>\n<ul>\n<li data-leveltext=\"%1.\" data-font=\"\" data-listid=\"1\" data-list-defn-props=\"{&quot;335552541&quot;:0,&quot;335559685&quot;:860,&quot;335559991&quot;:440,&quot;469769242&quot;:[65533,0],&quot;469777803&quot;:&quot;left&quot;,&quot;469777804&quot;:&quot;%1.&quot;,&quot;469777815&quot;:&quot;hybridMultilevel&quot;}\" aria-setsize=\"-1\" data-aria-posinset=\"3\" data-aria-level=\"1\"><a href=\"https:\/\/devblogs.microsoft.com\/dotnet-ch\/c12%e6%96%b0%e5%8a%9f%e8%83%bd%e5%90%88%e9%9b%86%e4%b8%89%ef%bc%9a%e4%bd%bf%e7%94%a8%e4%bb%bb%e6%84%8f%e7%b1%bb%e5%9e%8b%e7%9a%84%e5%88%ab%e5%90%8d%e9%87%8d%e6%9e%84c%e4%bb%a3%e7%a0%81\/\"><span data-contrast=\"auto\">\u4f7f\u7528\u4efb\u610f\u7c7b\u578b\u522b\u540d\u91cd\u6784<\/span><span data-contrast=\"auto\"> C# <\/span><span data-contrast=\"auto\">\u4ee3\u7801<\/span><span data-ccp-props=\"{&quot;134245417&quot;:false,&quot;335551550&quot;:6,&quot;335551620&quot;:6}\">\u00a0<\/span><\/a><\/li>\n<\/ul>\n<ul>\n<li data-leveltext=\"%1.\" data-font=\"\" data-listid=\"1\" data-list-defn-props=\"{&quot;335552541&quot;:0,&quot;335559685&quot;:860,&quot;335559991&quot;:440,&quot;469769242&quot;:[65533,0],&quot;469777803&quot;:&quot;left&quot;,&quot;469777804&quot;:&quot;%1.&quot;,&quot;469777815&quot;:&quot;hybridMultilevel&quot;}\" aria-setsize=\"-1\" data-aria-posinset=\"4\" data-aria-level=\"1\">\u4f7f\u7528\u9ed8\u8ba4 lambda \u53c2\u6570\u91cd\u6784C#\u4ee3\u7801\uff08\u672c\u7bc7\u6587\u7ae0\uff09<\/li>\n<\/ul>\n<p><span data-contrast=\"auto\">\u8fd9\u4e9b\u529f\u80fd\u662f\u6211\u4eec\u4e0d\u65ad\u52aa\u529b\u63d0\u9ad8\u4ee3\u7801\u53ef\u8bfb\u6027\u548c\u53ef\u7ef4\u62a4\u6027\u7684\u4e00\u90e8\u5206\u3002\u8ba9\u6211\u4eec\u8be6\u7ec6\u63a2\u7d22\u5b83\u4eec<\/span><span data-contrast=\"auto\">\uff01<\/span><span data-ccp-props=\"{&quot;134245417&quot;:false,&quot;335551550&quot;:6,&quot;335551620&quot;:6}\">\u00a0<\/span><\/p>\n<p><b><span data-contrast=\"auto\">\u9ed8\u8ba4<\/span><\/b><b><span data-contrast=\"auto\"> Lambda <\/span><\/b><b><span data-contrast=\"auto\">\u53c2\u6570<\/span><\/b>\ud83e\uddee<\/p>\n<p><span data-contrast=\"auto\">\u9ed8\u8ba4<\/span><span data-contrast=\"auto\"> lambda <\/span><span data-contrast=\"auto\">\u53c2\u6570\u662f<\/span><span data-contrast=\"auto\"> C# 12 <\/span><span data-contrast=\"auto\">\u4e2d\u7684\u4e00\u9879\u65b0\u529f\u80fd\uff0c\u5141\u8bb8\u5f00\u53d1\u4eba\u5458\u5728<\/span><span data-contrast=\"auto\"> lambda <\/span><span data-contrast=\"auto\">\u4e2d\u8868\u8fbe\u9ed8\u8ba4\u53c2\u6570\u503c\u3002\u6b64\u529f\u80fd\u662f<\/span><span data-contrast=\"auto\"> C# <\/span><span data-contrast=\"auto\">\u65b9\u6cd5\u4e2d\u73b0\u6709\u9ed8\u8ba4\u53c2\u6570\u529f\u80fd\u7684\u81ea\u7136\u6269\u5c55<\/span><span data-contrast=\"auto\">\u3002<\/span><span data-ccp-props=\"{&quot;134245417&quot;:false,&quot;335551550&quot;:6,&quot;335551620&quot;:6}\">\u00a0<\/span><\/p>\n<p><b><span data-contrast=\"auto\">C# 12 <\/span><\/b><b><span data-contrast=\"auto\">\u4e4b\u524d<\/span><\/b>\ud83d\udd70\ufe0f<\/p>\n<p><span data-contrast=\"auto\">\u5728<\/span><span data-contrast=\"auto\"> C# 12 <\/span><span data-contrast=\"auto\">\u4e4b\u524d\uff0c\u5f53\u60a8\u5b9a\u4e49\u9700\u8981\u63d0\u4f9b\u67d0\u79cd\u9ed8\u8ba4\u884c\u4e3a\u7684<\/span><span data-contrast=\"auto\"> lambda <\/span><span data-contrast=\"auto\">\u8868\u8fbe\u5f0f\u65f6\uff0c\u60a8\u5fc5\u987b\u4f7f\u7528\u7a7a\u5408\u5e76\u8fd0\u7b97\u7b26<\/span><span data-contrast=\"auto\"> (??) <\/span><span data-contrast=\"auto\">\u6216\u6761\u4ef6\u8fd0\u7b97\u7b26<\/span><span data-contrast=\"auto\"> (?:)<\/span><span data-contrast=\"auto\">\u3002\u8bf7\u67e5\u770b\u4ee5\u4e0b\u793a\u4f8b\uff1a<\/span><span data-ccp-props=\"{&quot;134245417&quot;:false,&quot;335551550&quot;:6,&quot;335551620&quot;:6}\">\u00a0<\/span><\/p>\n<pre class=\"prettyprint language-default\"><code class=\"language-default\">var IncrementBy = static (int source, int? increment) =&gt;\r\n{\r\n    \/\/ Same as source + (increment.HasValue ? increment.Value : 1)\r\n    return source + (increment ?? 1);\r\n};\r\n\r\nConsole.WriteLine(IncrementBy(5, null)); \/\/ 6\r\nConsole.WriteLine(IncrementBy(5, 2));    \/\/ 7<\/code><\/pre>\n<p><b><span data-contrast=\"auto\">\u4f7f\u7528<\/span><\/b><b><span data-contrast=\"auto\"> C# 12<\/span><\/b> <span data-contrast=\"auto\">\ud83e\udd13<\/span><span data-ccp-props=\"{&quot;134245417&quot;:false,&quot;335551550&quot;:6,&quot;335551620&quot;:6}\">\u00a0<\/span><\/p>\n<p><span data-contrast=\"auto\">\u76f8\u53cd\uff0c\u4f7f\u7528\u9ed8\u8ba4<\/span><span data-contrast=\"auto\"> lambda <\/span><span data-contrast=\"auto\">\u53c2\u6570\u540e\uff0c\u60a8\u53ef\u4ee5\u76f4\u63a5\u5728<\/span><span data-contrast=\"auto\"> lambda <\/span><span data-contrast=\"auto\">\u8868\u8fbe\u5f0f\u4e2d\u5b9a\u4e49<\/span><span data-contrast=\"auto\"> lambda <\/span><span data-contrast=\"auto\">\u53c2\u6570\u7684\u9ed8\u8ba4\u503c\u3002\u9ed8\u8ba4<\/span><span data-contrast=\"auto\"> lambda <\/span><span data-contrast=\"auto\">\u53c2\u6570\u7684\u8bed\u6cd5\u7c7b\u4f3c\u4e8e\u65b9\u6cd5\u4e2d\u9ed8\u8ba4\u53c2\u6570\u7684\u8bed\u6cd5\u3002\u9ed8\u8ba4\u503c\u5728\u53c2\u6570\u540d\u79f0\u548c\u7b49\u53f7<\/span><span data-contrast=\"auto\"> (=) <\/span><span data-contrast=\"auto\">\u540e\u6307\u5b9a\u3002\u8bf7\u67e5\u770b\u4ee5\u4e0b\u793a\u4f8b<\/span><span data-contrast=\"auto\">\uff1a<\/span><span data-ccp-props=\"{&quot;134245417&quot;:false,&quot;335551550&quot;:6,&quot;335551620&quot;:6}\">\u00a0<\/span><\/p>\n<pre class=\"prettyprint language-default\"><code class=\"language-default\">var IncrementBy = static (int source, int increment = 1) =&gt;\r\n{    \r\n    return source + increment;\r\n};\r\n\r\nConsole.WriteLine(IncrementBy(10));     \/\/ 11\r\nConsole.WriteLine(IncrementBy(10, 20)); \/\/ 30<\/code><\/pre>\n<p><span data-contrast=\"auto\">\u5f53\u6d89\u53ca\u9ed8\u8ba4\u53c2\u6570\u65f6\uff0c<\/span><span data-contrast=\"auto\">Lambda <\/span><span data-contrast=\"auto\">\u8868\u8fbe\u5f0f\u9075\u5faa\u4e0e\u65b9\u6cd5\u76f8\u540c\u7684\u89c4\u5219\u3002\u9ed8\u8ba4\u503c\u5fc5\u987b\u662f\u7f16\u8bd1\u65f6\u5e38\u91cf\uff0c\u5e76\u4e14\u5fc5\u987b\u4e0e\u53c2\u6570\u5177\u6709\u76f8\u540c\u7684\u7c7b\u578b\u3002\u9ed8\u8ba4\u503c\u5728\u7f16\u8bd1\u65f6\u8fdb\u884c\u8ba1\u7b97<\/span><span data-contrast=\"auto\">\uff0c<\/span><span data-contrast=\"auto\">\u5e76\u4e14\u5728\u8c03\u7528<\/span><span data-contrast=\"auto\"> lambda <\/span><span data-contrast=\"auto\">\u8868\u8fbe\u5f0f\u65f6\u53c2\u6570\u662f\u53ef\u9009\u7684<\/span><span data-contrast=\"auto\">\u3002<\/span><span data-ccp-props=\"{&quot;134245417&quot;:false,&quot;335551550&quot;:6,&quot;335551620&quot;:6}\">\u00a0<\/span><\/p>\n<pre class=\"prettyprint language-default\"><code class=\"language-default\">delegate int (int arg1, int arg2 = 1);<\/code><\/pre>\n<p><span data-contrast=\"auto\">\u8fd9\u610f\u5473\u7740\uff0c\u4ece\u6280\u672f\u4e0a\u8bb2\uff0c\u60a8\u53ef\u4ee5\u4f7f\u7528\u53c2\u6570\u7684\u540d\u79f0\u8c03\u7528<\/span><span data-contrast=\"auto\">Lambda<\/span><span data-contrast=\"auto\">\u8868\u8fbe\u5f0f\uff0c\u4f46\u5b83\u5fc5\u987b\u662f\u533f\u540d\u51fd\u6570\u751f\u6210\u7684\u540d\u79f0\u3002\u4f8b\u5982\uff0c\u4ee5\u4e0b\u6269\u5c55\u793a\u4f8b<\/span><span data-contrast=\"auto\">\uff1a<\/span><span data-ccp-props=\"{&quot;134245417&quot;:false,&quot;335551550&quot;:6,&quot;335551620&quot;:6}\">\u00a0<\/span><\/p>\n<pre class=\"prettyprint language-default\"><code class=\"language-default\">var IncrementByWithOffset = static (int source, int increment = 1, int offset = 100) =&gt;\r\n{    \r\n    return source + increment + offset;\r\n};\r\n\r\nConsole.WriteLine(IncrementByWithOffset(10));             \/\/ 111\r\nConsole.WriteLine(IncrementByWithOffset(10, 20));         \/\/ 130\r\nConsole.WriteLine(IncrementByWithOffset(10, 20, 0));      \/\/ 30\r\nConsole.WriteLine(IncrementByWithOffset(10, arg2: -100)); \/\/ 10\r\nConsole.WriteLine(IncrementByWithOffset(10, arg3: 0));    \/\/ 11<\/code><\/pre>\n<p><b><span data-contrast=\"auto\">ASP.NET Core Minimal API <\/span><\/b><b><span data-contrast=\"auto\">\u793a\u4f8b<\/span><\/b><span data-ccp-props=\"{&quot;134245417&quot;:false,&quot;335551550&quot;:6,&quot;335551620&quot;:6}\">\u00a0<\/span><\/p>\n<p><span data-contrast=\"auto\">\u8ba9\u6211\u4eec\u7814\u7a76\u4e00\u4e2a\u793a\u4f8b\uff0c\u5176\u4e2d\u6211\u4eec\u6709\u4e00\u4e2a\u4f7f\u7528\u9ed8\u8ba4<\/span><span data-contrast=\"auto\"> lambda <\/span><span data-contrast=\"auto\">\u53c2\u6570\u7684<\/span><span data-contrast=\"auto\"> ASP.NET Core Minimal API\u3002<\/span><span data-contrast=\"auto\">\u6765\u5230<\/span><span data-contrast=\"auto\"> Visual Studio 2022 <\/span><span data-contrast=\"auto\">\u4e2d\u7684<\/span><b><span data-contrast=\"auto\">\u6587\u4ef6<\/span><\/b><span data-contrast=\"auto\"> &gt; <\/span><b><span data-contrast=\"auto\">\u65b0\u5efa<\/span><\/b> <span data-contrast=\"auto\">&gt; <\/span><b><span data-contrast=\"auto\">\u9879\u76ee<\/span><\/b><span data-contrast=\"auto\">\u7684\u5bf9\u8bdd\u6846\uff0c\u521b\u5efa\u4e00\u4e2a\u65b0\u7684<\/span><span data-contrast=\"auto\"> ASP.NET Core Web API <\/span><span data-contrast=\"auto\">\u9879\u76ee\u3002\u6216\u8005\uff0c\u60a8\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b<\/span><span data-contrast=\"auto\"> .NET CLI <\/span><span data-contrast=\"auto\">\u547d\u4ee4\u6765\u521b\u5efa\u65b0\u9879\u76ee<\/span><span data-contrast=\"auto\">\uff1a<\/span><span data-ccp-props=\"{&quot;134245417&quot;:false,&quot;335551550&quot;:6,&quot;335551620&quot;:6}\">\u00a0<\/span><\/p>\n<pre class=\"prettyprint language-default\"><code class=\"language-default\">dotnet new webapi -n WebApi<\/code><\/pre>\n<p><span data-contrast=\"auto\">\u6b64\u6a21\u677f\u521b\u5efa\u4e00\u4e2a\u5177\u6709\u5355\u4e2a<\/span><span data-contrast=\"auto\"> \/weatherforecast <\/span><span data-contrast=\"auto\">\u7aef\u70b9\u7684\u65b0<\/span><span data-contrast=\"auto\"> ASP.NET Core Web API <\/span><span data-contrast=\"auto\">\u9879\u76ee\u3002<\/span><span data-contrast=\"auto\"> \/weatherforecast <\/span><span data-contrast=\"auto\">\u7aef\u70b9\u8fd4\u56de\u4e94\u4e2a\u968f\u673a\u5929\u6c14\u9884\u62a5\u7684\u6570\u7ec4\uff0c\u8bf7\u67e5\u770b\u4ee5\u4e0b<\/span><span data-contrast=\"auto\"> Program.cs <\/span><span data-contrast=\"auto\">\u6587\u4ef6\u4e2d\u7684\u6a21\u677f\u4ee3\u7801<\/span><span data-contrast=\"auto\">\uff1a<\/span><span data-ccp-props=\"{&quot;134245417&quot;:false,&quot;335551550&quot;:6,&quot;335551620&quot;:6}\">\u00a0<\/span><\/p>\n<pre class=\"prettyprint language-default\"><code class=\"language-default\">var builder = WebApplication.CreateBuilder(args);\r\n\r\n\/\/ Add services to the container.\r\n\/\/ Learn more about configuring Swagger\/OpenAPI at https:\/\/aka.ms\/aspnetcore\/swashbuckle\r\nbuilder.Services.AddEndpointsApiExplorer();\r\nbuilder.Services.AddSwaggerGen();\r\n\r\nvar app = builder.Build();\r\n\r\n\/\/ Configure the HTTP request pipeline.\r\nif (app.Environment.IsDevelopment())\r\n{\r\n    app.UseSwagger();\r\n    app.UseSwaggerUI();\r\n}\r\n\r\napp.UseHttpsRedirection();\r\n\r\nvar summaries = new[]\r\n{\r\n    \"Freezing\", \"Bracing\", \"Chilly\", \"Cool\", \"Mild\", \"Warm\", \"Balmy\", \"Hot\", \"Sweltering\", \"Scorching\"\r\n};\r\n\r\napp.MapGet(\"\/weatherforecast\", () =&gt;\r\n{\r\n    var forecast = Enumerable.Range(1, 5).Select(index =&gt;\r\n        new WeatherForecast\r\n        (\r\n            DateOnly.FromDateTime(DateTime.Now.AddDays(index)),\r\n            Random.Shared.Next(-20, 55),\r\n            summaries[Random.Shared.Next(summaries.Length)]\r\n        ))\r\n        .ToArray();\r\n    return forecast;\r\n})\r\n.WithName(\"GetWeatherForecast\")\r\n.WithOpenApi();\r\n\r\napp.Run();\r\n\r\ninternal record WeatherForecast(DateOnly Date, int TemperatureC, string? Summary)\r\n{\r\n    public int TemperatureF =&gt; 32 + (int)(TemperatureC \/ 0.5556);\r\n}<\/code><\/pre>\n<p><span data-contrast=\"auto\">\u8fd9\u91cc\u6709\u4e00\u6bb5\u6765\u81ea\u6a21\u677f\u7684\u4ee3\u7801\uff0c\u4f46\u5b83\u5e76\u4e0d\u662f\u6211\u4eec\u771f\u6b63\u8981\u5173\u6ce8\u7684\u91cd\u70b9\u3002\u6211\u4eec\u53ea\u9700\u5173\u6ce8<\/span><span data-contrast=\"auto\"> MapGet <\/span><span data-contrast=\"auto\">\u65b9\u6cd5\uff0c\u56e0\u4e3a\u5b83\u5c06\u6211\u4eec\u7684<\/span><span data-contrast=\"auto\"> lambda <\/span><span data-contrast=\"auto\">\u529f\u80fd\u6620\u5c04\u5230<\/span><span data-contrast=\"auto\"> HTTP GET <\/span><span data-contrast=\"auto\">\u8c03\u7528<\/span><span data-contrast=\"auto\">\u3002<\/span><span data-ccp-props=\"{&quot;134245417&quot;:false,&quot;335551550&quot;:6,&quot;335551620&quot;:6}\">\u00a0<\/span><\/p>\n<pre class=\"prettyprint language-default\"><code class=\"language-default\">app.MapGet(\"\/weatherforecast\", () =&gt;\r\n{\r\n    var forecast = Enumerable.Range(1, 5).Select(index =&gt;\r\n        new WeatherForecast\r\n        (\r\n            DateOnly.FromDateTime(DateTime.Now.AddDays(index)),\r\n            Random.Shared.Next(-20, 55),\r\n            summaries[Random.Shared.Next(summaries.Length)]\r\n        ))\r\n        .ToArray();\r\n    return forecast;\r\n})\r\n.WithName(\"GetWeatherForecast\")\r\n.WithOpenApi();<\/code><\/pre>\n<p><span data-contrast=\"auto\">\/weatherforecast <\/span><span data-contrast=\"auto\">\u7aef\u70b9\u8fd4\u56de\u4e00\u4e2a\u5305\u542b\u4e94\u4e2a\u5929\u6c14\u9884\u62a5\u7684\u6570\u7ec4\u3002<\/span><span data-contrast=\"auto\">Enumerable.Range(1, 5) <\/span><span data-contrast=\"auto\">\u65b9\u6cd5\u8c03\u7528\u4e2d\u7684\u786c\u7f16\u7801<\/span><span data-contrast=\"auto\"> 5 <\/span><span data-contrast=\"auto\">\u53ef\u4ee5\u88ab\u9ed8\u8ba4<\/span><span data-contrast=\"auto\"> lambda <\/span><span data-contrast=\"auto\">\u53c2\u6570\u66ff\u6362\uff0c\u4ee5\u4e0b\u662f\u66f4\u65b0\u540e\u7684\u4ee3\u7801\u7247\u6bb5<\/span><span data-contrast=\"auto\">\uff1a<\/span><span data-ccp-props=\"{&quot;134245417&quot;:false,&quot;335551550&quot;:6,&quot;335551620&quot;:6}\">\u00a0<\/span><\/p>\n<pre class=\"prettyprint language-default\"><code class=\"language-default\">app.MapGet(\"\/weatherforecast\", (int days = 5) =&gt;\r\n{\r\n    \/\/ Safety check to ensure the days parameter is \r\n    \/\/ at least 1, but no more than 50.\r\n    var count = days is &gt; 0 and &lt;= 50 \r\n        ? days\r\n        : 5;\r\n\r\n    var forecast = Enumerable.Range(1, count).Select(index =&gt;\r\n        new WeatherForecast\r\n        (\r\n            DateOnly.FromDateTime(DateTime.Now.AddDays(index)),\r\n            Random.Shared.Next(-20, 55),\r\n            summaries[Random.Shared.Next(summaries.Length)]\r\n        ))\r\n        .ToArray();\r\n\r\n    return forecast;\r\n})<\/code><\/pre>\n<p><span data-contrast=\"auto\">\u4f7f\u7528\u4fee\u6539\u540e\u7684\u4ee3\u7801\u540e<\/span><span data-contrast=\"auto\">\uff0cMapGet <\/span><span data-contrast=\"auto\">\u65b9\u6cd5\u73b0\u5728\u63a5\u53d7\u4e00\u4e2a\u9ed8\u8ba4\u503c\u4e3a<\/span><span data-contrast=\"auto\"> 5 <\/span><span data-contrast=\"auto\">\u7684\u53ef\u9009<\/span><span data-contrast=\"auto\"> days <\/span><span data-contrast=\"auto\">\u53c2\u6570\u3002\u56e0\u6b64\uff0c\u867d\u7136\u4ecd\u7136\u5b58\u5728\u76f8\u540c\u7684\u9ed8\u8ba4\u884c\u4e3a\uff0c\u4f46\u6211\u4eec\u5411\u6d88\u8d39\u8005\u516c\u5f00\u4e86\u6b64\u53c2\u6570<\/span><span data-contrast=\"auto\">\u3002days <\/span><span data-contrast=\"auto\">\u53c2\u6570\u53ef\u4ee5\u4f5c\u4e3a\u67e5\u8be2\u5b57\u7b26\u4e32\u4f20\u9012\u7ed9<\/span><span data-contrast=\"auto\"> API\u3002<\/span><span data-contrast=\"auto\">\u4f8b\u5982\uff0c\u4ee5\u4e0b<\/span><span data-contrast=\"auto\">HTTP<\/span><span data-contrast=\"auto\">\u8bf7\u6c42\uff0c\u8be5\u8bf7\u6c42\u8bf7\u6c42<\/span><span data-contrast=\"auto\">21<\/span><span data-contrast=\"auto\">\u5929\u7684\u5929\u6c14\u9884\u62a5<\/span><span data-contrast=\"auto\">\uff1a<\/span><span data-ccp-props=\"{&quot;134245417&quot;:false,&quot;335551550&quot;:6,&quot;335551620&quot;:6}\">\u00a0<\/span><\/p>\n<pre class=\"prettyprint language-default\"><code class=\"language-default\">GET \/weatherforecast?days=21 HTTP\/1.1\r\nHost: localhost:7240\r\nScheme: https<\/code><\/pre>\n<p><span data-contrast=\"auto\">\u5f53\u67e5\u8be2\u5b57\u7b26\u4e32\u4e2d\u672a\u63d0\u4f9b<\/span><span data-contrast=\"auto\"> days <\/span><span data-contrast=\"auto\">\u53c2\u6570\u65f6\uff0c\u5c06\u4f7f\u7528\u6b64\u9ed8\u8ba4\u503c\u3002<\/span><span data-contrast=\"auto\"> days <\/span><span data-contrast=\"auto\">\u53c2\u6570\u7528\u4e8e\u6307\u5b9a\u5e94\u751f\u6210\u5929\u6c14\u9884\u62a5\u7684\u5929\u6570\u3002<\/span> <span data-contrast=\"auto\">\u6709\u5173<\/span><span data-contrast=\"auto\"> ASP.NET Core <\/span><span data-contrast=\"auto\">Minimal\u202f<\/span><span data-contrast=\"auto\">API <\/span><span data-contrast=\"auto\">\u7684\u8be6\u7ec6\u4fe1\u606f\uff0c\u8bf7\u53c2\u9605<\/span><a href=\"https:\/\/learn.microsoft.com\/en-us\/aspnet\/core\/fundamentals\/minimal-apis\/parameter-binding?view=aspnetcore-8.0#optional-parameters\"><span data-contrast=\"none\">\u53ef\u9009\u53c2\u6570<\/span><\/a><span data-contrast=\"auto\">\u3002<\/span><span data-ccp-props=\"{&quot;134245417&quot;:false,&quot;335551550&quot;:6,&quot;335551620&quot;:6}\">\u00a0<\/span><\/p>\n<p><b><span data-contrast=\"auto\">\u4e0b\u4e00\u6b65\u8ba1\u5212<\/span><\/b><span data-ccp-props=\"{&quot;134245417&quot;:false,&quot;335551550&quot;:6,&quot;335551620&quot;:6}\">\u00a0<\/span><\/p>\n<p><span data-contrast=\"auto\">\u8fd9\u5c31\u662f\u5173\u4e8e<\/span><span data-contrast=\"auto\"> C# 12 <\/span><span data-contrast=\"auto\">\u90e8\u5206\u65b0\u7279\u6027\u7cfb\u5217\u6587\u7ae0\u7684\u5168\u90e8\u5185\u5bb9\u4e86\uff01\uff01\u6211\u5e0c\u671b\u60a8\u559c\u6b22\u4e86\u89e3\u8fd9\u4e9b\u65b0\u529f\u80fd\u4ee5\u53ca\u5b83\u4eec\u5982\u4f55\u5e2e\u52a9\u60a8\u91cd\u6784\u4ee3\u7801<\/span><span data-contrast=\"auto\">\u3002<\/span><span data-ccp-props=\"{&quot;134245417&quot;:false,&quot;335551550&quot;:6,&quot;335551620&quot;:6}\">\u00a0<\/span><\/p>\n<p><span data-contrast=\"auto\">\u5728\u672c\u6587\u4e2d\uff0c\u60a8\u4e86\u89e3\u4e86<\/span><span data-contrast=\"auto\"> C# 12 <\/span><span data-contrast=\"auto\">\u4e2d\u7684\u9ed8\u8ba4<\/span><span data-contrast=\"auto\"> lambda <\/span><span data-contrast=\"auto\">\u53c2\u6570\u529f\u80fd\u3002\u6b64\u529f\u80fd\u5141\u8bb8\u5f00\u53d1\u4eba\u5458\u5728<\/span><span data-contrast=\"auto\"> lambda <\/span><span data-contrast=\"auto\">\u4e2d\u8868\u8fbe\u9ed8\u8ba4\u53c2\u6570\u503c\u3002\u8bf7\u52a1\u5fc5\u5728\u60a8\u81ea\u5df1\u7684\u4ee3\u7801\u4e2d\u5c1d\u8bd5\u4e00\u4e0b\uff01\u5982\u9700\u66f4\u591a\u8d44\u6e90\uff0c\u6211\u5efa\u8bae\u60a8\u67e5\u770b\u4ee5\u4e0b\u94fe\u63a5\uff1a<\/span><span data-ccp-props=\"{&quot;134245417&quot;:false,&quot;335551550&quot;:6,&quot;335551620&quot;:6}\">\u00a0<\/span><\/p>\n<ul>\n<li data-leveltext=\"\uf0b7\" data-font=\"Symbol\" data-listid=\"3\" data-list-defn-props=\"{&quot;335552541&quot;:1,&quot;335559685&quot;:860,&quot;335559991&quot;:440,&quot;469769226&quot;:&quot;Symbol&quot;,&quot;469769242&quot;:[8226],&quot;469777803&quot;:&quot;left&quot;,&quot;469777804&quot;:&quot;\uf0b7&quot;,&quot;469777815&quot;:&quot;hybridMultilevel&quot;}\" aria-setsize=\"-1\" data-aria-posinset=\"1\" data-aria-level=\"1\"><a href=\"https:\/\/learn.microsoft.com\/en-us\/dotnet\/csharp\/language-reference\/operators\/lambda-expressions\"><span data-contrast=\"auto\">C# <\/span><span data-contrast=\"auto\">\u8bed\u8a00\u53c2\u8003\uff1a<\/span><span data-contrast=\"auto\">Lambda <\/span><span data-contrast=\"none\">\u8868\u8fbe\u5f0f<\/span><\/a><span data-ccp-props=\"{&quot;134245417&quot;:false,&quot;335551550&quot;:6,&quot;335551620&quot;:6}\">\u00a0<\/span><\/li>\n<\/ul>\n<ul>\n<li data-leveltext=\"\uf0b7\" data-font=\"Symbol\" data-listid=\"3\" data-list-defn-props=\"{&quot;335552541&quot;:1,&quot;335559685&quot;:860,&quot;335559991&quot;:440,&quot;469769226&quot;:&quot;Symbol&quot;,&quot;469769242&quot;:[8226],&quot;469777803&quot;:&quot;left&quot;,&quot;469777804&quot;:&quot;\uf0b7&quot;,&quot;469777815&quot;:&quot;hybridMultilevel&quot;}\" aria-setsize=\"-1\" data-aria-posinset=\"2\" data-aria-level=\"1\"><a href=\"https:\/\/learn.microsoft.com\/en-us\/dotnet\/csharp\/language-reference\/proposals\/csharp-12.0\/lambda-method-group-defaults\"><span data-contrast=\"auto\">C# <\/span><span data-contrast=\"auto\">\u8bed\u8a00\u53c2\u8003\uff1a<\/span><span data-contrast=\"auto\">Lambda <\/span><span data-contrast=\"none\">\u65b9\u6cd5\u7ec4\u9ed8\u8ba4\u503c<\/span><\/a><span data-ccp-props=\"{&quot;134245417&quot;:false,&quot;335551550&quot;:6,&quot;335551620&quot;:6}\">\u00a0<\/span><\/li>\n<\/ul>\n<p>\u5982\u679c\u60a8\u6709\u4efb\u4f55\u6280\u672f\u95ee\u9898\uff0c\u6b22\u8fce\u6765<a href=\"https:\/\/learn.microsoft.com\/zh-cn\/answers\/tags\/309\/csharp\" target=\"_blank\" rel=\"noopener\">Microsoft Q&amp;A<\/a>\u00a0\u63d0\u95ee\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u672c\u6587\u7ffb\u8bd1\u4e8eDavid Pine\u7684\u8fd9\u7bc7\u6587\u7ae0:Refactor your code with default lambda parameters\u00a0\u3002 \u672c\u6587\u662f\u63a2\u8ba8 C# 12\u7684\u5404\u79cd\u529f\u80fd\u7684\u56db\u7bc7\u7cfb\u5217\u6587\u7ae0\u4e2d\u7684\u6700\u540e\u4e00\u7bc7\u3002\u5728\u8fd9\u7bc7\u6587\u7ae0\u4e2d\uff0c\u6211\u4eec\u5c06\u63a2\u8ba8\u201c\u9ed8\u8ba4 lambda \u53c2\u6570\u201d\u529f\u80fd\uff0c\u4f7f\u5f00\u53d1\u4eba\u5458\u80fd\u591f\u5728 lambda \u8868\u8fbe\u5f0f\u4e2d\u4f7f\u7528\u9ed8\u8ba4\u53c2\u6570\u503c\u3002\u672c\u7cfb\u5217\u6db5\u76d6\u4e86\u5f88\u591a\u5185\u5bb9\uff1a\u00a0 \u4f7f\u7528\u4e3b\u6784\u9020\u51fd\u6570\u91cd\u6784 C# \u4ee3\u7801\u00a0 \u4f7f\u7528\u96c6\u5408\u8868\u8fbe\u5f0f\u91cd\u6784 C# \u4ee3\u7801\u00a0 \u4f7f\u7528\u4efb\u610f\u7c7b\u578b\u522b\u540d\u91cd\u6784 C# \u4ee3\u7801\u00a0 \u4f7f\u7528\u9ed8\u8ba4 lambda \u53c2\u6570\u91cd\u6784C#\u4ee3\u7801\uff08\u672c\u7bc7\u6587\u7ae0\uff09 \u8fd9\u4e9b\u529f\u80fd\u662f\u6211\u4eec\u4e0d\u65ad\u52aa\u529b\u63d0\u9ad8\u4ee3\u7801\u53ef\u8bfb\u6027\u548c\u53ef\u7ef4\u62a4\u6027\u7684\u4e00\u90e8\u5206\u3002\u8ba9\u6211\u4eec\u8be6\u7ec6\u63a2\u7d22\u5b83\u4eec\uff01\u00a0 \u9ed8\u8ba4 Lambda \u53c2\u6570\ud83e\uddee \u9ed8\u8ba4 lambda \u53c2\u6570\u662f C# 12 \u4e2d\u7684\u4e00\u9879\u65b0\u529f\u80fd\uff0c\u5141\u8bb8\u5f00\u53d1\u4eba\u5458\u5728 lambda \u4e2d\u8868\u8fbe\u9ed8\u8ba4\u53c2\u6570\u503c\u3002\u6b64\u529f\u80fd\u662f C# \u65b9\u6cd5\u4e2d\u73b0\u6709\u9ed8\u8ba4\u53c2\u6570\u529f\u80fd\u7684\u81ea\u7136\u6269\u5c55\u3002\u00a0 C# 12 \u4e4b\u524d\ud83d\udd70\ufe0f \u5728 C# 12 \u4e4b\u524d\uff0c\u5f53\u60a8\u5b9a\u4e49\u9700\u8981\u63d0\u4f9b\u67d0\u79cd\u9ed8\u8ba4\u884c\u4e3a\u7684 lambda \u8868\u8fbe\u5f0f\u65f6\uff0c\u60a8\u5fc5\u987b\u4f7f\u7528\u7a7a\u5408\u5e76\u8fd0\u7b97\u7b26 (??) \u6216\u6761\u4ef6\u8fd0\u7b97\u7b26 (?:)\u3002\u8bf7\u67e5\u770b\u4ee5\u4e0b\u793a\u4f8b\uff1a\u00a0 var IncrementBy [&hellip;]<\/p>\n","protected":false},"author":99475,"featured_media":749,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[2,10],"class_list":["post-769","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-dotnet-ch","tag-net","tag-c"],"acf":[],"blog_post_summary":"<p>\u672c\u6587\u7ffb\u8bd1\u4e8eDavid Pine\u7684\u8fd9\u7bc7\u6587\u7ae0:Refactor your code with default lambda parameters\u00a0\u3002 \u672c\u6587\u662f\u63a2\u8ba8 C# 12\u7684\u5404\u79cd\u529f\u80fd\u7684\u56db\u7bc7\u7cfb\u5217\u6587\u7ae0\u4e2d\u7684\u6700\u540e\u4e00\u7bc7\u3002\u5728\u8fd9\u7bc7\u6587\u7ae0\u4e2d\uff0c\u6211\u4eec\u5c06\u63a2\u8ba8\u201c\u9ed8\u8ba4 lambda \u53c2\u6570\u201d\u529f\u80fd\uff0c\u4f7f\u5f00\u53d1\u4eba\u5458\u80fd\u591f\u5728 lambda \u8868\u8fbe\u5f0f\u4e2d\u4f7f\u7528\u9ed8\u8ba4\u53c2\u6570\u503c\u3002\u672c\u7cfb\u5217\u6db5\u76d6\u4e86\u5f88\u591a\u5185\u5bb9\uff1a\u00a0 \u4f7f\u7528\u4e3b\u6784\u9020\u51fd\u6570\u91cd\u6784 C# \u4ee3\u7801\u00a0 \u4f7f\u7528\u96c6\u5408\u8868\u8fbe\u5f0f\u91cd\u6784 C# \u4ee3\u7801\u00a0 \u4f7f\u7528\u4efb\u610f\u7c7b\u578b\u522b\u540d\u91cd\u6784 C# \u4ee3\u7801\u00a0 \u4f7f\u7528\u9ed8\u8ba4 lambda \u53c2\u6570\u91cd\u6784C#\u4ee3\u7801\uff08\u672c\u7bc7\u6587\u7ae0\uff09 \u8fd9\u4e9b\u529f\u80fd\u662f\u6211\u4eec\u4e0d\u65ad\u52aa\u529b\u63d0\u9ad8\u4ee3\u7801\u53ef\u8bfb\u6027\u548c\u53ef\u7ef4\u62a4\u6027\u7684\u4e00\u90e8\u5206\u3002\u8ba9\u6211\u4eec\u8be6\u7ec6\u63a2\u7d22\u5b83\u4eec\uff01\u00a0 \u9ed8\u8ba4 Lambda \u53c2\u6570\ud83e\uddee \u9ed8\u8ba4 lambda \u53c2\u6570\u662f C# 12 \u4e2d\u7684\u4e00\u9879\u65b0\u529f\u80fd\uff0c\u5141\u8bb8\u5f00\u53d1\u4eba\u5458\u5728 lambda \u4e2d\u8868\u8fbe\u9ed8\u8ba4\u53c2\u6570\u503c\u3002\u6b64\u529f\u80fd\u662f C# \u65b9\u6cd5\u4e2d\u73b0\u6709\u9ed8\u8ba4\u53c2\u6570\u529f\u80fd\u7684\u81ea\u7136\u6269\u5c55\u3002\u00a0 C# 12 \u4e4b\u524d\ud83d\udd70\ufe0f \u5728 C# 12 \u4e4b\u524d\uff0c\u5f53\u60a8\u5b9a\u4e49\u9700\u8981\u63d0\u4f9b\u67d0\u79cd\u9ed8\u8ba4\u884c\u4e3a\u7684 lambda \u8868\u8fbe\u5f0f\u65f6\uff0c\u60a8\u5fc5\u987b\u4f7f\u7528\u7a7a\u5408\u5e76\u8fd0\u7b97\u7b26 (??) \u6216\u6761\u4ef6\u8fd0\u7b97\u7b26 (?:)\u3002\u8bf7\u67e5\u770b\u4ee5\u4e0b\u793a\u4f8b\uff1a\u00a0 var IncrementBy 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