Hi Everyone,
Yesterday i faced an issue while working with multiple update panels on same page.I found that we can't perform simultanious Asynchronous Requests using multiple update panels on same page. When we submit multiple request then last request always wins. It was quite unexpected behavior of update panel and against the Asynchronous programming models.
However, if we don't want 'Last request Win' behaviour then we can do that by canceling the request if another request is already in progress.
All you need to do is.
1. Handle Sys.WebForms.PageRequestManage's InitalizeRequest Event on client side.
2. Use Sys.WebForms.PageRequestManager.get_isInAsyncPostBack() method to know either another request is in progress or not.
3. Cancel the request if another request is already in progress.
Here is sample code:
ASPX
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="TestAJAXApplication._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></title>
<style type="text/css">
.style1
{
width: 100%;
}
</style>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<script type="text/javascript">
var prm = Sys.WebForms.PageRequestManager.getInstance();
prm.add_initializeRequest(initializeRequest);
function initializeRequest(sender, args) {
if (prm.get_isInAsyncPostBack()) {
alert("Another Request is already in progress");
args.set_cancel(true);
}
}
</script>
<table class="style1">
<tr>
<td>
<asp:UpdatePanel ID="upOne" runat="server" ChildrenAsTriggers="true">
<ContentTemplate>
<asp:Label ID="lblOne" runat="server" Text="Label"></asp:Label><br />
<asp:Button ID="btnUpdateOne" Text="Update" runat="server"
onclick="btnUpdateOne_Click" />
</ContentTemplate>
</asp:UpdatePanel>
</td>
</tr>
<tr>
<td>
<asp:UpdatePanel ID="upTwo" runat="server" ChildrenAsTriggers="true">
<ContentTemplate>
<asp:Label ID="lblTwo" runat="server" Text="Label"></asp:Label><br />
<asp:Button ID="btnUpdateTwo" Text="Update" runat="server"
onclick="btnUpdateTwo_Click" />
</ContentTemplate>
</asp:UpdatePanel>
</td>
</tr>
</table>
</div>
</form>
</body>
</html>
Code Behined:
namespace TestAJAXApplication
{
public partial class _Default : System.Web.UI.Page
{
protected void btnUpdateOne_Click(object sender, EventArgs e)
{
System.Threading.Thread.Sleep(2500);
lblOne.Text = string.Format("Updates On: {0}", DateTime.Now.ToShortTimeString());
}
protected void btnUpdateTwo_Click(object sender, EventArgs e)
{
System.Threading.Thread.Sleep(2500);
lblTwo.Text = string.Format("Updates On: {0}", DateTime.Now.ToShortTimeString());
}
}
}
Last month my article "Windows Authentication Using Form Authentication" was published on codeproject.com and dotnetslakers.com.
Here are the links of the article
http://www.codeproject.com/KB/aspnet/WinAuthusingFormAuth.aspx
http://dotnetslackers.com/articles/aspnet/Windows-Authentication-using-Form-Authentication.aspx
I am also writing some more articles for these websites, hopefully they will be publish in this month ( If i will complete them on time :) ).