C#的委托

using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;

namespace codeTest
{
delegate void NumDelegate(int num);
class Program
{

static void Main(string[] args)
{
AClass _a = new AClass();
_a.cwdelegate = _a.AddNum;
_a.cwdelegate(20);
NumDelegate num20delegate = new NumDelegate(Add20);
Console.WriteLine("-------------------------------------------");
NumDelegate adddelegate =new NumDelegate(_a.AddNum);
NumDelegate subdelegate = new NumDelegate(_a.SubNum);
NumDelegate num30delegate = adddelegate + subdelegate;
num30delegate(30);
Console.WriteLine("-------------------------------------------");
num30delegate += num20delegate;
num30delegate(30);
Console.WriteLine("-------------------------------------------");
num30delegate += adddelegate;
//去掉最后一个adddelegate
num30delegate -= adddelegate;
num30delegate(30);
Console.ReadLine();
}
static void Add20(int num)
{
Console.WriteLine(string.Format("Add20: {0}", num));
}
}

class AClass
{
public int result = 100;
public delegate void CWDelegate(int num);
public CWDelegate cwdelegate;
public void AddNum(int num)
{
Console.WriteLine(string.Format("AddNum: {0}",num));
}

public void SubNum(int num)
{
Console.WriteLine(string.Format("SubNum: {0}", num));
}
}

}