C# delegate 学习

/Files/longren629/DelegateDemo.zip

1:操作类

using  System;
using  System.Data;
using  System.Configuration;
using  System.Web;
using  System.Web.Security;
using  System.Web.UI;
using  System.Web.UI.WebControls;
using  System.Web.UI.WebControls.WebParts;
using  System.Web.UI.HtmlControls;

/**/ /// <summary>
/// Demo 的摘要说明
/// </summary>
public   class  Demo
{
    内部变量#region 内部变量
    /**//// <summary>
   /// 省
   /// </summary>
    private string _province;
    /**//// <summary>
    /// 市
    /// </summary>
    private string _town;
    # endregion
    代理#region  代理

    /**//// <summary>
    /// 添加城市
    /// </summary>
    /// <param name="newtown"></param>
    public delegate void AddTownDelegate(string newtown);
    /**//// <summary>
    /// 移除省
    /// </summary>
    /// <param name="newprovince"></param>
    public delegate void RemoveProvinceDelegate(string newprovince);

    public AddTownDelegate AddTown;
    public RemoveProvinceDelegate RemoveProvince;

    #endregion
    属性#region 属性
    /**//// <summary>
    /// 省
    /// </summary>
    public string Province
    {
        get
        {
            return _province;
        }
    }
    /**//// <summary>
    /// 市
    /// </summary>
    public string Town
    {
        get
        {
            return _town;
        }
    }
#endregion
    # region 实例方法

    public void AddNewTown()
    {
        if (this.AddTown != null)
        {
            this.AddTown(Province);
        }
    }
    public void RemoveOldProvince()
    {
        if (this.RemoveProvince != null)
        {
            this.RemoveProvince(Town);
        }
    }

    #endregion
    构造函数#region 构造函数
    public Demo()
    {
        //
        // TODO: 在此处添加构造函数逻辑
        //
    }
    public Demo(string province, string town)
    {
        this._province = province;
        this._town = town;
    }
    #endregion
}

2:页面

<% @ Page Language="C#" AutoEventWireup="true"  CodeFile="Default.aspx.cs" Inherits="_Default"  %>

<! DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd" >

< html  xmlns ="http://www.w3.org/1999/xhtml"   >
< head  runat ="server" >
     < title > Delegate学习实例 </ title >
</ head >
< body >
     < form  id ="form1"  runat ="server" >
       < asp:Button  ID ="Button1"  runat ="server"  Text ="添加成都同时利用Delegate添加四川"  OnClick ="Button1_Click"   />
         < br  />
         < asp:Button  ID ="Button2"  runat ="server"  Text ="移除四川同时利用Delegate移除成都"  OnClick ="Button2_Click"   />< br  />
         < asp:ListBox  ID ="ListBox1"  runat ="server"  Width ="330px"  Height ="328px" ></ asp:ListBox >
      
       
   
     </ form >
</ body >
</ html >

3,页面代码隐藏类

using  System;
using  System.Data;
using  System.Configuration;
using  System.Web;
using  System.Web.Security;
using  System.Web.UI;
using  System.Web.UI.WebControls;
using  System.Web.UI.WebControls.WebParts;
using  System.Web.UI.HtmlControls;

public  partial  class  _Default : System.Web.UI.Page 
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        Demo bll = new Demo("四川", "成都");
        bll.AddTown += new Demo.AddTownDelegate(AddProvince);
        this.ListBox1.Items.Add(bll.Town);
        bll.AddNewTown();   
    
    }
    protected void AddProvince(string Province)
    {
        this.ListBox1.Items.Add(Province);
    }

    protected void RemovedCity(string City)
    {
        this.ListBox1.Items.Remove(new ListItem(City));
    }

    protected void Button2_Click(object sender, EventArgs e)
    {
        Demo bll = new Demo("四川", "成都");
        bll.RemoveProvince += new Demo.RemoveProvinceDelegate(RemovedCity);
        this.ListBox1.Items.Remove(new ListItem(bll.Province));
        bll.RemoveOldProvince();
    }
}