ASP.NET Tutorial/Ajax/Asynchronous Event

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Aborting the Previous Asynchronous Postback

   <source lang="csharp">

<%@ Page Language="C#" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <script runat="server"> 

   protected void btnGetFortune_Click(object sender, EventArgs e)
   {
       System.Threading.Thread.Sleep(3000); // wait 3 seconds
       lblFortune.Text = String.Format("At {0:T}, the oracle says: ", DateTime.Now);
       Random rnd = new Random();
       switch (rnd.Next(4))
       {
           case 0:
               lblFortune.Text += "You"re doomed!";
               break;
           case 1:
               lblFortune.Text += "Good luck is around the corner.";
               break;
           case 2:
               lblFortune.Text += "Don"t leave home.";
               break;
           case 3:
               lblFortune.Text += "Buy stock today.";
               break;
       }
   }

</script> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> 

   <title>UpdatePanel Abort</title>

</head> <body> 

   <form id="form1" runat="server">

       <asp:ScriptManager ID="ScriptManager1" runat="server" />
       <asp:UpdatePanel ID="up1" runat="server">
       <ContentTemplate>
           <asp:Button
               id="btnGetFortune"
               Text="Get Fortune"
               OnClick="btnGetFortune_Click"
               Runat="server" />
           <asp:Button
               id="btnCancel"
               Text="Cancel"
               Enabled="false"
               Runat="server" />
               

               <asp:Label ID="lblFortune" runat="server" />
       </ContentTemplate>
       </asp:UpdatePanel>

   </form>
   <script type="text/javascript">
   var prm = Sys.WebForms.PageRequestManager.getInstance();
   prm.add_initializeRequest(prm_initializeRequest);
   function prm_initializeRequest(sender, args)
   {
       if (args.get_postBackElement().id == "btnCancel")
       {
           prm.abortPostBack();
           alert("Fortune Aborted!");
       }
       else
       {
           $get("btnCancel").disabled = false;
       }
    }
   </script>

</body> </html></source>


Canceling the Current Asynchronous Postback

   <source lang="csharp">

<%@ Page Language="C#" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <script runat="server"> 

   protected void btnSubmit_Click(object sender, EventArgs e)
   {
       System.Threading.Thread.Sleep(3000); // sleep 3 seconds
   }

</script> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> 

   <title>UpdatePanel Cancel</title>

</head> <body> 

   <form id="form1" runat="server">
   <asp:ScriptManager ID="ScriptManager1" runat="server" />
   <asp:UpdatePanel ID="up1" UpdateMode="Conditional" runat="server">
   <ContentTemplate>
       <%= DateTime.Now.ToString("T") %>
       <asp:Button
           id="btnSubmit1"
           Text="Submit 1"
           OnClick="btnSubmit_Click"
           Runat="server"/>
   </ContentTemplate>
   </asp:UpdatePanel>
   <asp:UpdatePanel ID="up2" UpdateMode="Conditional" runat="server">
   <ContentTemplate>
       <%= DateTime.Now.ToString("T") %>
       <asp:Button
           id="btnSubmit2"
           Text="Submit 2"
           OnClick="btnSubmit_Click"
           Runat="server" />
   </ContentTemplate>
   </asp:UpdatePanel>
   </form>
   <script type="text/javascript">
   var prm = Sys.WebForms.PageRequestManager.getInstance();
   prm.add_initializeRequest( prm_initializeRequest );
   function prm_initializeRequest(sender, args)
   {
       if (prm.get_isInAsyncPostBack())
       {
           alert("Still Processing First Request");
           args.set_cancel(true);
       }
   }
   </script>

</body> </html></source>


Passing Additional Information During an Asynchronous Postback

   <source lang="csharp">

<%@ Page Language="C#" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <script runat="server"> 

   protected void dtlProduct_DataBound(object sender, EventArgs e)
   {
       string productTitle = (string)DataBinder.Eval(dtlProduct.DataItem, "Title");
       if (sm1.IsInAsyncPostBack)
       {
           sm1.RegisterDataItem(Head1, productTitle);
       }
       else
       {
           Head1.Title = productTitle;
           hTitle.InnerHtml = productTitle;
       }
   }

</script> <html xmlns="http://www.w3.org/1999/xhtml"> <head id="Head1" runat="server"> 

   <title>UpdatePanel DataItem</title>

</head> <body> 

   <form id="form1" runat="server">

   <asp:ScriptManager
       id="sm1"
       Runat="server" />


   <asp:UpdatePanel
       id="upSearch"
       Runat="server">
       <ContentTemplate>
       <asp:DetailsView
           id="dtlProduct"
           DataSourceID="srcProducts"
           AllowPaging="true"
           Runat="server" OnDataBound="dtlProduct_DataBound" />
       </ContentTemplate>
   </asp:UpdatePanel>
   <asp:SqlDataSource
       id="srcProducts"
       ConnectionString="<%$ ConnectionStrings:con %>"
       SelectCommand="SELECT Id,Title,Director FROM Product"
       Runat="server" />

   </form>
   <script type="text/javascript">
   var prm = Sys.WebForms.PageRequestManager.getInstance();
   prm.add_pageLoaded( prm_pageLoaded );
   function prm_pageLoaded(sender, args)
   {
       if (prm.get_isInAsyncPostBack())
       {
           var productTitle = args.get_dataItems()["Head1"];
           document.title = productTitle;
           $get("hTitle").innerHTML = productTitle;
       }
   }
   </script>

</body> </html></source>

Источник — «http://nfex.ru/index.php?title=ASP.NET_Tutorial/Ajax/Asynchronous_Event&oldid=3016»