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Editorial Team
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Asked: 2026-05-30T11:50:05+00:00

I m building a website where i need to update project counter whenever its

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I m building a website where i need to update project counter whenever its updated in DB. when ever any user add a new project, the project counter should automatically update in browser, but i don’t want to send ajax request to server again and again to get count from DB and then update counter in web browser.

I want something similar “how facebook notification updated” automatically without refreshing page or sending any ajax request, i know there are using some PUSH technology but i not sure how it works.

It will be very great if someone provide some Example code to achieve this.

Thanks…

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1 Answer

  1. Editorial Team

    Have you considered using SignalR?

    http://www.hanselman.com/blog/AsynchronousScalableWebApplicationsWithRealtimePersistentLongrunningConnectionsWithSignalR.aspx

    http://signalr.net/

    Here is the sample code based on a quick POC after reading some SO replies and above articles. Hope it helps.

    • Create a new empty ASP.NET web application project

    • Add the SignalR package via NuGet

    • Add a UserCounter.cs with following code. Just need to inherit the class from Hub base class.

      using SignalR.Hubs;
public class UserCounter : Hub { }

    • Add a Default.aspx with following code:

      <!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">
</head>
<body>
    <form id="form1" runat="server">
        <div>
            Number of users currently online - <b><span id="noOfUsers">0</span> users</b>
            <br />
            <a target="_blank" href="UpdateNoOfUsers.aspx">Change number of users</a>
        </div>
    </form>
    </body>
    <script src="Scripts/jquery-1.6.4.js" type="text/javascript"></script>
    <script src="Scripts/jquery.signalR.js" type="text/javascript"></script>
    <script src="/signalr/hubs" type="text/javascript"></script>

    <script type="text/javascript">
    $(function () {
        var usc = $.connection.userCounter;

        usc.noOfUsersUpdated = function (message) {
            $('#noOfUsers').text(message);
        };

        $.connection.hub.start();
    });
</script>

</html>

    • Add a UpdateNoOfUsers.aspx with following code:

      <!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">
</head>
    <body>
        <form id="form1" runat="server">
            <div>
                No. of users: <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
                <asp:Button ID="Button1" runat="server" Text="Button" onclick="Button1_Click" />
            </div>
        </form>
    </body>
    </html>

    • Add an event-handler for button-click for button in UpdateNoOfUsers.aspx 

      using SignalR;
using SignalR.Infrastructure;
using SignalR.Hosting.AspNet;

protected void Button1_Click(object sender, EventArgs e)
{
    IConnectionManager connectionManager = AspNetHost.DependencyResolver.Resolve<IConnectionManager>();
    dynamic clients = connectionManager.GetClients<UserCounter>();
    clients.noOfUsersUpdated(TextBox1.Text);
}

    • Run the application after setting “Default.aspx” as the start up page

    • Click on the “Change number of users” link to open a new browser window

    • Enter a number in text-box and click on the button to see the value change in base window! Open this page in some other browser and see the same behaviour!

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