System.Action委托(C# 3.5+)

Action：相当于一种无参数传递的委托，从Framework 3.5开始加如，简化了委托调用代码：

Delegate原代码：

using System;
using System.Windows.Forms;

public delegate void DisplayMessage();

public class testTestDelegate
{
   public static void Main()
   {
      DisplayMessage showMethod = DisplayToWindow();
      showMethod();
   }
   public static void DisplayToWindow()
   {
      MessageBox.Show("Antiquity Way:Hello World");
   }

} 

Action新代码： 

using System;
using System.Windows.Forms;

public class testTestDelegate
{
   public static void Main()
   {
      Action showMethod = DisplayToWindow;
      showMethod();
   }
   public static void DisplayToWindow()
   {
      MessageBox.Show("Action Way：Hello World");
   }

} 

更简洁的方法：（Lambda方法）

using System;
using System.Windows.Forms;

public class testTestDelegate
{
   public static void Main()
   {
      Action showMethod = () =>{ MessageBox.Show("Action Way：Hello World"); };
      showMethod();
   }

} 

参考MSDN：http://msdn.microsoft.com/zh-cn/library/system.action.aspx