写了一个自定义控件（但是不是很明白！继续学习！）

 1using System;
 2using System.Web.UI;
 3using System.Web.UI.WebControls;
 4using System.ComponentModel;
 5
 6namespace kongjiantest
 7{
 8    /**//// <summary>
 9    /// ConfirmButton 的摘要说明。
10    /// </summary>
11    [DefaultProperty("PopupMessage"),ToolboxData("<{0}:ConfirmButton runat=server></{0}:ConfirmButton>")]
12    public class ConfirmButton : Button
13    {
14        
15        // TODO: 在此处添加构造函数逻辑
16        [ Bindable(true),
17        Category("Appearance"),
18        DefaultValue("")]
19        public string PopupMessage
20        {
21            get
22            {
23                //检查ViewState中是否存在改项目
24                object popupMessage=this.ViewState["PopupMessage"];
25                if(popupMessage!=null)
26                    return this.ViewState["PopupMessage"].ToString();
27                else
28                    return "真的要删除吗?";
29            }
30            set
31            {
32                //指定ViewState变量
33                ViewState["PopupMessage"]=value;
34            }
35
36        }
37    
38        protected override void  AddAttributesToRender(HtmlTextWriter writer)
39
40        { 
41            base.AddAttributesToRender(writer);
42            string script=@" return confirm (""%%POPUP_MESSAGE%%"");";
43            script=script.Replace("%%POPUP_MESSAGE%%",this.PopupMessage.Replace("\"","\\\""));
44            writer.AddAttribute(HtmlTextWriterAttribute.Onclick,script);
45
46
47        }
48
49
50    
51    }
52}
53
54
55