将lambda表达式附加到C#程序的主要方法的结果是什么？

Question

简而言之,我想知道为什么以下代码编译并运行.

using System;

namespace ConsoleApplication
{
    public class Program
    {
        public static void Main(string[] args) => Console.WriteLine("Hello World!");
    }
}

我对C#的有限知识告诉我,创建了一个名为Main的Delegate,由于某种原因,编译器/运行时接受此Delegate作为程序的有效起点.我的理解是否正确？是否有特定原因会使用这样的声明？

我碰到这个看罗斯林源代码,发现这里.

// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.

using System.IO;
using Microsoft.CodeAnalysis.CommandLine;
using Roslyn.Utilities;
using System;

namespace Microsoft.CodeAnalysis.CSharp.CommandLine
{
    public class Program
    {
        public static int Main(string[] args)
            => Main(args, Array.Empty<string>());

        public static int Main(string[] args, string[] extraArgs)
            => DesktopBuildClient.Run(args, extraArgs, RequestLanguage.CSharpCompile, Csc.Run, new DesktopAnalyzerAssemblyLoader());

        public static int Run(string[] args, string clientDir, string workingDir, string sdkDir, string tempDir, TextWriter textWriter, IAnalyzerAssemblyLoader analyzerLoader)
            => Csc.Run(args, new BuildPaths(clientDir: clientDir, workingDir: workingDir, sdkDir: sdkDir, tempDir: tempDir), textWriter, analyzerLoader);
    }
}

谢谢.

Answer 1

public static void Main(string[] args) => Console.WriteLine("Hello World!");

不是委托,因为没有delegate关键字.这只是一种方法/功能.它的编写方式只是编写简单方法/函数的简便方法,在C#6中引入.它被称为表达式身体函数.请参阅C#:新增和改进的C#6.0.