自定义控件的事件

自定义控件的事件根据需要有两种方式来引发

1
继承IPostBackDataHandler 接口
实现
bool LoadPostData(string postDataKey, NameValueCollection postCollection);
void RaisePostDataChangedEvent();

两个方法,大致都是这样
bool IPostBackDataHandler.LoadPostData(string postDataKey, NameValueCollection postCollection)
{
    string text1 = postCollection [postDataKey] ;
    if(text1  != 自定义控件的 text or value or selectID.....)
    {
        text or value or selectID..... = text1  ;
        return true;
    }
    return false;
}

void IPostBackDataHandler.RaisePostDataChangedEvent()
{
    this.OnClick(EventArgs.Empty); //OnSelectedIndexChanged(EventArgs.Empty);.....冒泡出去
}

2
继承IPostBackEventHandler 接口

实现
 void RaisePostBackEvent(string eventArgument);
方法
大致实现方法:
 void  IPostBackEventHandler.RaisePostBackEvent(string eventArgument)
{
    OnClick(EventArg);..................
}
//给html控件注册脚本.表明回发
我要使用 __doPostBack(eventTarget, eventArgument) 这个方法进行处理.
这个方法进行注册如下:
...Attributes.Add("OnClick", this.Page.GetPostBackClientEvent(this, eventArgument));


如:

button的:

protected virtual void RaisePostBackEvent(string eventArgument)
            {
            base.ValidateEvent(this.UniqueID, eventArgument);
            if (this.CausesValidation)
            {
            this.Page.Validate(this.ValidationGroup);
            }
            this.OnClick(EventArgs.Empty);
            this.OnCommand(new CommandEventArgs(this.CommandName, this.CommandArgument));
            }
            

他注册的 事件脚本 在这个方法里面
protected override void AddAttributesToRender(HtmlTextWriter writer)

 

看代码:

 

 

 1 private void ProcessPostData(NameValueCollection postData, bool fBeforeLoad)
 2 {
 3     if (this._changedPostDataConsumers == null)
 4     {
 5         this._changedPostDataConsumers = new ArrayList();
 6     }
 7     if (postData != null)
 8     {
 9         foreach (string str in postData)
10         {
11             if ((str == null) || IsSystemPostField(str))
12             {
13                 continue;
14             }
15             Control control = this.FindControl(str);
16             if (control == null)
17             {
18                 if (fBeforeLoad)
19                 {
20                     if (this._leftoverPostData == null)
21                     {
22                         this._leftoverPostData = new NameValueCollection();
23                     }
24                     this._leftoverPostData.Add(str, null);
25                 }
26                 continue;
27             }
28             IPostBackDataHandler postBackDataHandler = control.PostBackDataHandler;
29             if (postBackDataHandler == null)
30             {
31                 if (control.PostBackEventHandler != null)
32                 {
33                     this.RegisterRequiresRaiseEvent(control.PostBackEventHandler);
34                 }
35             }
36             else
37             {
38                 if ((postBackDataHandler != null) && postBackDataHandler.LoadPostData(str, this._requestValueCollection))
39                 {
40                     this._changedPostDataConsumers.Add(control);
41                 }
42                 if (this._controlsRequiringPostBack != null)
43                 {
44                     this._controlsRequiringPostBack.Remove(str);
45                 }
46             }
47         }
48     }
49     ArrayList list = null;
50     if (this._controlsRequiringPostBack != null)
51     {
52         foreach (string str2 in this._controlsRequiringPostBack)
53         {
54             Control control2 = this.FindControl(str2);
55             if (control2 != null)
56             {
57                 IPostBackDataHandler handler2 = control2._adapter as IPostBackDataHandler;
58                 if (handler2 == null)
59                 {
60                     handler2 = control2 as IPostBackDataHandler;
61                 }
62                 if (handler2 == null)
63                 {
64                     throw new HttpException(SR.GetString("Postback_ctrl_not_found", new object[] { str2 }));
65                 }
66                 if (handler2.LoadPostData(str2, this._requestValueCollection))
67                 {
68                     this._changedPostDataConsumers.Add(control2);
69                 }
70                 continue;
71             }
72             if (fBeforeLoad)
73             {
74                 if (list == null)
75                 {
76                     list = new ArrayList();
77                 }
78                 list.Add(str2);
79             }
80         }
81         this._controlsRequiringPostBack = list;
82     }
83 }
84 
85  

 

 

 1 internal void RaiseChangedEvents()
 2 {
 3     if (this._changedPostDataConsumers != null)
 4     {
 5         for (int i = 0; i < this._changedPostDataConsumers.Count; i++)
 6         {
 7             Control control = (Control) this._changedPostDataConsumers[i];
 8             if (control != null)
 9             {
10                 IPostBackDataHandler postBackDataHandler = control.PostBackDataHandler;
11                 if (((control == null) || control.IsDescendentOf(this)) && ((control != null) && (control.PostBackDataHandler != null)))
12                 {
13                     postBackDataHandler.RaisePostDataChangedEvent();
14                 }
15             }
16         }
17     }
18 }
19 
20  
21 
22  

 

 

 1 private void RaisePostBackEvent(NameValueCollection postData)
 2 {
 3     if (this._registeredControlThatRequireRaiseEvent != null)
 4     {
 5         this.RaisePostBackEvent(this._registeredControlThatRequireRaiseEvent, null);
 6     }
 7     else
 8     {
 9         string str = postData["__EVENTTARGET"];
10         bool flag = !string.IsNullOrEmpty(str);
11         if (flag || (this.AutoPostBackControl != null))
12         {
13             Control control = null;
14             if (flag)
15             {
16                 control = this.FindControl(str);
17             }
18             if ((control != null) && (control.PostBackEventHandler != null))
19             {
20                 string eventArgument = postData["__EVENTARGUMENT"];
21                 this.RaisePostBackEvent(control.PostBackEventHandler, eventArgument);
22             }
23         }
24         else
25         {
26             this.Validate();
27         }
28     }
29 }
30 
31