Many readers have had difficulty with the post SignalR VB.NET Push Notification as they have installed the latest version 2.0. We will require some changes to the old post to make it work.
"..No more RouteTable.Routes.MapConnection but the new Owin MapSignalR..."
Let us review the steps...
"..No more RouteTable.Routes.MapConnection but the new Owin MapSignalR..."
Step 1
Install gituhub Package from Package Manager Console
PM> Install-Package Microsoft.AspNet.SignalR
Step 2
Add a new Class to project and create a PersistantConnection:
Imports System.Web
Imports System.Threading.Tasks
Imports Microsoft.AspNet.SignalR
Public Class NotificationConnection
Inherits PersistentConnection
Protected Overrides Function OnConnected(request As IRequest, connectionId As String) As System.Threading.Tasks.Task
Return MyBase.OnConnected(request, connectionId)
End Function
End Class
Step 3
Add our class for notifications (for simplicity we create note with a value and a time)
Imports Microsoft.AspNet.SignalR
Public Class Notification
Private _ExamValue As Int32
Private _Data As String
Public Property ExamValue As Int32
Get
Return _ExamValue
End Get
Set(value As Int32)
_ExamValue = value
End Set
End Property
Public Property Data As String
Get
Return _Data
End Get
Set(value As String)
_Data = value
End Set
End Property
End Class
Step 4 (Here is the update!!!)
No longer use the file Global.asax.vb. We add a new class for mapping connection.
No more RouteTable.Routes.MapConnection but the new Owin MapSignalR
Imports Owin
Imports Microsoft.AspNet.SignalR
Imports Microsoft.AspNet.SignalR.Infrastructure
Imports System.Threading
Imports System.Threading.Tasks
<Assembly: Microsoft.Owin.OwinStartup(GetType(SignalR.Startup))>
Public Class Startup
Public Sub Configuration(app As IAppBuilder)
app.MapSignalR(Of NotificationConnection)("/NotificationConnection")
Task.Factory.StartNew(Function()
Dim connectonManager As IConnectionManager = GlobalHost.DependencyResolver.Resolve(Of IConnectionManager)()
Dim connection = connectonManager.GetConnectionContext(Of NotificationConnection)()
While True
Dim item = New Notification() With { _
.Data = DateTime.Now.ToString("hh:mm:ss"), _
.ExamValue = CInt(Math.Ceiling(Rnd() * 100))
}
connection.Connection.Broadcast(item)
Thread.Sleep(1000)
End While
End Function)
End Sub
End Class
Step 5 (also here a small change !!!)
In html page we have to change the reference to the old script with the new one for SignalR.
<script src="scripts/jquery-1.6.4.js" type="text/javascript"></script>
<script src="scripts/json2.js" type="text/javascript"></script>
<!--<script src="scripts/jquery.signalR-1.1.1.js" type="text/javascript"></script>-->
<script src="Scripts/jquery.signalR-2.0.0.min.js"></script>
<script type="text/javascript">
var output;
$(document).ready(function () {
output = $("#output");
});
var data;
var options;
connection = $.connection('/NotificationConnection');
connection.received(function (dataItem) {
var newItem = dataItem;
output.text("Received exam value: " + newItem.Data + "," + newItem.ExamValue);
});
connection.start();
</script>
<body>
<h2>Laboratory Exams Monitoring</h2>
<div id="output"></div>
</body>
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