1.__doPostBack("id","")方法

2.GetPostBackEventReference方法作用

3.客户端如何触发服务器端控件的事件

 

右边提供程序用此方法实现在客户端单击按钮后,禁用此按钮,直到程序运行完毕再开启按钮。(单击右边下载)

 

下面再举个小例子.

前台页面

有个服务器控件 <asp:Button id="Button1" runat="server" Text="Button"></asp:Button>

一个客户端控件用来触发服务器端

<a href="#" onclick="document.getElementById('Button1').click()">触发服务器端按钮事件</a>

 (2)

利用GetPostBackEventReference给客户端生成__doPostBack()

前台 

<a href="#" onclick="<%=PostBack()%>">触发服务器端按钮事件</a>

 后台

protected string PostBack()

        {

            return this.Page.GetPostBackEventReference(this.Button1,"haha");

        }

通过__EVENTARGUMENT="haha"可以判断是不是点了那个链接的PostBack

把Button1的按钮事件这么写:

if(Request["__EVENTARGUMENT" ]=="haha")

            {

                Response.Write("这个是链接的PostBack");

            }

            else

            {

                Response.Write("这个不是链接的PostBack");

            }

 以下这个是微软MSDN上的例子:

public class MyControl : Control, IPostBackEventHandler

{

  

   // Create an integer property that is displayed when

   // the page that contains this control is requested

   // and save it to the control's ViewState property.

   public int Number

   {

     get

     {

       if ( ViewState["Number"] !=null )

          return (int) ViewState["Number"];

       return 50;

     }

     set

     {

       ViewState["Number"] = value;

     }       

   }

   // Implement the RaisePostBackEvent method from the

   // IPostBackEventHandler interface. If 'inc' is passed

   // to this method, it increases the Number property by one.

   // If 'dec' is passed to this method, it decreases the

   // Number property by one.

   public void RaisePostBackEvent(string eventArgument)

   {

     if ( eventArgument == "inc" )

     Number = Number + 1;

     if ( eventArgument == "dec" )

     Number = Number - 1;

   }

  

[System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name="FullTrust")]

   protected override void Render(HtmlTextWriter writer)

   {

     // Converts the Number property to a string and

 // writes it to the containing page.

     writer.Write("The Number is " + Number.ToString() + " (" );

 // Uses the GetPostBackEventReference method to pass

 // 'inc' to the RaisePostBackEvent method when the link

 // this code creates is clicked.

     writer.Write("<a href=\"javascript:" + Page.GetPostBackEventReference(this,"inc") + "\">Increase Number</a>");

     writer.Write(" or ");

 // Uses the GetPostBackEventReference method to pass

 // 'dec' to the RaisePostBackEvent method when the link

 // this code creates is clicked.

     writer.Write("<a href=\"javascript:" + Page.GetPostBackEventReference(this,"dec") + "\">Decrease Number</a>");

   }

}