I Have Problem Displaying Signalr Changing Data It Only Changes One Row Again And Again I Want To Display All Rows That Are Changing. My Code Is Posted Below

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ASPX.cs

C#

public partial class Messages : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
SendNotifications();
}

public void SendNotifications()
{
string message = string.Empty;
string conStr = ConfigurationManager.ConnectionStrings["TestDB"].ConnectionString;

using (SqlConnection connection = new SqlConnection(conStr))
{
string SqlConnection= "SELECT Message FROM [dbo].[DummyData]";

using (SqlCommand command = new SqlCommand(query, connection))
{
command.Notification = null;
SqlDependency dependency = new SqlDependency(command);
dependency.OnChange += new OnChangeEventHandler(dependency_OnChange);
connection.Open();
SqlDataReader reader = command.ExecuteReader();

if (reader.HasRows)
{
reader.Read();
message = reader[0].ToString();
}
}
}
NotificationsHub nHub = new NotificationsHub();
nHub.NotifyAllClients(message);
}

private void dependency_OnChange(object sender, SqlNotificationEventArgs e)
{
if (e.Type == SqlNotificationType.Change)
{
SendNotifications();
}
}
}
}

ASPX

ASP.NET

<script>
        $(function () {
            var notify = $.connection.notificationsHub;
            notify.client.displayNotification = function (msg) {
                $("#GridView1").html(msg);
            };

            $.connection.hub.start();
        });
    </script>
</head>
<body>
    <form id="form1" runat="server">
        <div>
            <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataSourceID="SqlDataSource1">
                <Columns>
                    <asp:BoundField DataField="Message" HeaderText="Message" SortExpression="Message" />
                    <asp:BoundField DataField="Id" HeaderText="Id" SortExpression="Id" />
                    <asp:BoundField DataField="Mail" HeaderText="Mail" SortExpression="Mail" />
                </Columns>
            </asp:GridView>
            <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:TestConnectionString %>" SelectCommand="SELECT [Message], [Id], [Mail] FROM [DummyData]"></asp:SqlDataSource>
        </div>

NotificationHub.cs

C#

    public class NotificationsHub : Hub
    {
        public void NotifyAllClients(string msg)
        {
            IHubContext context = GlobalHost.ConnectionManager.GetHubContext<NotificationsHub>();
            context.Clients.All.displayNotification(msg);
        }
    }
}

Posted 27-Nov-15 20:36pm

Member 11893772

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Shmuel Zang · Accepted Answer · 2015-11-28T20:47:00

Solution 1

That's because you replace the content of your #GridView1 element instead of appending to it...

You can see this chat example: http://www.asp.net/signalr/overview/getting-started/tutorial-getting-started-with-signalr-and-mvc. It seems like it's dealing with the same issue.

Posted 28-Nov-15 20:47pm

Shmuel Zang

Comments

Member 11893772 29-Nov-15 7:31am

please i didn't get it could u show me wat code i have missed

Shmuel Zang 29-Nov-15 8:22am

In your code you replace all the content of your element. You should keep its content and, just append to it. And, since you want to manage your grid in the client side, instead of using an ASP.NET WebForms control that is managed by the server, it's can be more convenient to use simple HTML tags that can be managed in the client side. Go over the given chat example. You can see how they append an li element (for each message) to an ul element. In your case, if you want to show a grid, you can use a table (and add tr elements) instead of a list.