using System;
 using System.Collections.Generic;
 using System.Text; 
 namespace TestApp
 {
   /// <summary>
  /// 委托
   /// </summary>
   /// <param name="s1"></param>
   /// <param name="s2"></param>
   /// <returns></returns>
   public delegate string ProcessDelegate(string s1, string s2);
 
   class Program
   {
     static void Main(string[] args)
     {
       /* 调用方法 */
       ProcessDelegate pd = new ProcessDelegate(new Test().Process);
       Console.WriteLine(pd("Text1", "Text2"));
     }
   }
 
   public class Test
   {
     /// <summary>
     /// 方法
     /// </summary>
     /// <param name="s1"></param>
     /// <param name="s2"></param>
     /// <returns></returns>
     public string Process(string s1,string s2)
     {
       return s1 + s2;
     }
   }
 }

using System;
using System.Collections.Generic;
using System.Text;

namespace TestApp
{
  /// <summary>
  /// 委托
  /// </summary>
  /// <param name="s1"></param>
  /// <param name="s2"></param>
  /// <returns></returns>
  public delegate string ProcessDelegate<T,S>(T s1, S s2);

  class Program
  {
    static void Main(string[] args)
    {
      /* 调用方法 */
      ProcessDelegate<string,int> pd = new ProcessDelegate<string,int>(new Test().Process);
      Console.WriteLine(pd("Text1", 100));
    }
  }

  public class Test
  {
    /// <summary>
    /// 方法
    /// </summary>
    /// <param name="s1"></param>
    /// <param name="s2"></param>
    /// <returns></returns>
    public string Process(string s1,int s2)
    {
      return s1 + s2;
    }
  }
}

using System;
using System.Collections.Generic;
using System.Text;

namespace TestApp
{
  /// <summary>
  /// 委托
  /// </summary>
  /// <param name="s1"></param>
  /// <param name="s2"></param>
  /// <returns></returns>
  public delegate void ProcessDelegate(object sender, EventArgs e);

  class Program
  {
    

    static void Main(string[] args)
    {
      /* 第一步执行 */
      Test t = new Test();
      /* 关联事件方法，相当于寻找到了委托人 */
      t.ProcessEvent += new ProcessDelegate(t_ProcessEvent);
      /* 进入Process方法 */
      Console.WriteLine(t.Process()); 

      Console.Read();
    }

    static void t_ProcessEvent(object sender, EventArgs e)
    {
      Test t = (Test)sender;
      t.Text1 = "Hello";
      t.Text2 = "World";
    }
  }

  public class Test
  {
    private string s1;

    public string Text1
    {
      get { return s1; }
      set { s1 = value; }
    }

    private string s2;

    public string Text2
    {
      get { return s2; }
      set { s2 = value; }
    }


    public event ProcessDelegate ProcessEvent;

    void ProcessAction(object sender, EventArgs e)
    {
      if (ProcessEvent == null)
        ProcessEvent += new ProcessDelegate(t_ProcessEvent);
      ProcessEvent(sender, e);
    }

    //如果没有自己指定关联方法，将会调用该方法抛出错误
    void t_ProcessEvent(object sender, EventArgs e)
    {
      throw new Exception("The method or operation is not implemented.");
    }

    void OnProcess()
    {
      ProcessAction(this, EventArgs.Empty);
    }

    public string Process()
    {
      OnProcess();
      return s1 + s2;
    }
  }
}

using System;
using System.Collections.Generic;
using System.Text;

namespace TestApp
{
  /// <summary>
  /// 委托
  /// </summary>
  /// <param name="s1"></param>
  /// <param name="s2"></param>
  /// <returns></returns>
  public delegate string ProcessDelegate(string s1, string s2);

  class Program
  {
    static void Main(string[] args)
    {
      /* 调用方法 */
      Test t = new Test();
      string r1 = t.Process("Text1", "Text2", new ProcessDelegate(t.Process1));
      string r2 = t.Process("Text1", "Text2", new ProcessDelegate(t.Process2));
      string r3 = t.Process("Text1", "Text2", new ProcessDelegate(t.Process3));

      Console.WriteLine(r1);
      Console.WriteLine(r2);
      Console.WriteLine(r3);
    }
  }

  public class Test
  {
    public string Process(string s1,string s2,ProcessDelegate process)
    {
      return process(s1, s2);
    }

    public string Process1(string s1, string s2)
    {
      return s1 + s2;
    }

    public string Process2(string s1, string s2)
    {
      return s1 + Environment.NewLine + s2;
    }

    public string Process3(string s1, string s2)
    {
      return s2 + s1;
    }
  }
}