c# 事件委托小例子

希望对初学者有点帮助 

using System; 
using System.Collections.Generic; 
using System.ComponentModel; 
using System.Data; 
using System.Drawing; 
using System.Text; 
using System.Windows.Forms; 

namespace QQAutoMan 
...{ 
    public partial class frmMain : Form 
    ...{ 
        //声明一个委托 
        public delegate void ReceivedEventHandler(object sender, System.EventArgs e); 
        //声明一个事件 
        public event ReceivedEventHandler Received; 
        // 用以触发Received事件 
        protected virtual void OnReceived(EventArgs e) 
        ...{ 
            if (this.Received != null) 
                this.Received(this, e); 
        } 

        private string _data = ""; 
        // Data属性 
        public string data 
        ...{ 
            get ...{ return this._data; } 
            set 
            ...{ 
                this._data = value; 
                // 数据改变时触发Received事件 
                this.OnReceived(new EventArgs()); 
            } 
        } 



        public frmMain() 
        ...{ 
            InitializeComponent(); 
        } 


        private void frmMain_Load(object sender, EventArgs e) 
        ...{ 
            this.Received += new ReceivedEventHandler(showdata); 
        } 

        private void showdata(object sender, System.EventArgs e) 
        ...{ 
            MessageBox.Show("收到你发来的数据:" + this.data); 
        } 

        private void button1_Click(object sender, EventArgs e) 
        ...{ 
            this.data = "abcd"; 
        } 
    } 
}