SendOrPostCallback 委托

public delegate void SendOrPostCallback(
	Object state
)

参数

state

类型：object
传递给委托的对象。

表示在消息即将被调度到同步上下文时要调用的方法。

SendOrPostCallback 表示在消息即将被调度到同步上下文时要执行的回调方法。创建委托，方法是将回调方法传递给SendOrPostCallback 构造函数。您的方法必须具有此处所显示的签名。

要做一件 void 类型返回值的，说白了，就是无返回值的，参数是 object的，也就是说，想传啥，就传啥，无法无天了，尺度很大！ 网上搜索了一下，有例子，可以很好的证明，这个应用的好处，如下

// Visual C#

using System;
using System.Threading;

namespace SynchronizationContextSampleCS
{
    class BankAccount
    {
        public decimal balance;
        public void Deposit(decimal amount)
        {
            balance += amount;
        }
        public void Withdraw(decimal amount)
        {
            balance -= amount;
        }
    }
    class Program
    {
        static BankAccount account;
        static void Main(string[] args)
        {
            account = new BankAccount();
            SendOrPostCallback deposit = new SendOrPostCallback(Deposit);
            SendOrPostCallback withdraw = new SendOrPostCallback(Withdraw);
            SynchronizationContext ctx = new SynchronizationContext();
            ctx.Post(deposit, 500);
            ctx.Post(withdraw, 500);
            Console.ReadLine();
        }
        static void Withdraw(object state)
        {
            Console.WriteLine("Withdraw: current balance = {0:C}", account.balance);
            account.Withdraw(decimal.Parse(state.ToString()));
            Console.WriteLine("Withdraw: new balance = {0:C}", account.balance);
        }
        static void Deposit(object state)
        {
            Console.WriteLine("Withdraw: current balance = {0:C}", account.balance);
            account.Deposit(decimal.Parse(state.ToString()));
            Console.WriteLine("Deposit: new balance = {0:C}", account.balance);
        }
    }
}

转载自 张玉华

 http://blog.sina.com.cn/s/blog_5eded52b0100e583.html?retcode=0