In this article you will learn how to begin work with SignalR and how to exchange messages among multiples users.
What SignalR is: SignalR is an ASP.Net server library for adding real-time functionality to a web application. This includes client libraries for JavaScript and other clients.
Getting Started
The get started with SignalR:
- Start Visual Studio
- Create a new website
- Provide the name and location of website
- Click "Next"
Now add a new SignalR Hub class and give a name of class and click "Add".
Note: You will probably get this error message when you add the class:
"This template attempted to load component assembly 'NuGet.VisualStudio.Interop, Version=*, Culture=neutral, PublicKeyToken=*"
Follow this blog to remove this problem:
http://www.c-sharpcorner.com/Blogs/11651/%E2%80%98this-template-attempted-to-load-component-assembly-nuget-v.aspx
Or you can also add SignalR to a project by opening the "Tools" | "Library Package Manager" | "Package Manager Console" and running the command: "install-package Microsoft.AspNet.SignalR". Now again add the SignalR class.
![img1.jpg]()
Image 1.
As you can see, many SignalR assemblies have been added in the Bin folder, so you are good to go.
![img2.jpg]()
Image 2.
Now it is time to work on HubClass.
First of all add this namespace:
using Microsoft.AspNet.SignalR;
And now add this method:
public class ChatHub : Hub
{
public void Send(string name, string message)
{
Clients.All.broadcastMessage(name,message);
}
}
Now add these namespaces in the global.asax file:
<%@ Import Namespace="System.Web.Routing" %>
<%@ Import Namespace="Microsoft.AspNet.SignalR" %>
Add this code in the "application_start" event:
RouteTable.Routes.MapHubs();
Now add a new HTML page and give a name and click "Ok".
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>SignalR Simple Message Broadcast Sample</title>
</head>
<body>
<div style="background-color: #C0C0C0">
<input type="text" id="messagetext" />
<input type="button" id="btnsendmessage" value="Broadcast message" />
<input type="hidden" id="displayname" />
<ul id="loadmessages">
</ul>
</div>
<!--Script references. -->
<!--Reference the jQuery library. -->
<script src="/Scripts/jquery-1.8.2.min.js" ></script>
<!--Reference the SignalR library. -->
<script src="/Scripts/jquery.signalR-1.0.0.js"></script>
<!--Reference the autogenerated SignalR hub script. -->
<script src="/signalr/hubs"></script>
<!--Add script to update the page and send messages.-->
<script type="text/javascript">
$(function () {
// Declare a proxy to reference the hub.
var chat = $.connection.chatHub;
// Create a function that the hub can call to broadcast messages.
chat.client.broadcastMessage = function (name, message) {
// Html encode display name and message.
var encodedName = $('<div />').text(name).html();
var encodedMsg = $('<div />').text(message).html();
// Add the message to the page.
$('#loadmessages').append('<li><strong>' + encodedName
+ '</strong>: ' + encodedMsg + '</li>');
};
// Get the user name and store it to prepend to messages.
$('#displayname').val(prompt('Enter your name:', ''));
// Set initial focus to message input box.
$('#messagetext').focus();
// Start the connection.
$.connection.hub.start().done(function () {
$('#btnsendmessage').click(function () {
// Call the Send method on the hub.
chat.server.send($('#displayname').val(), $('#messagetext').val());
// Clear text box and reset focus for next comment.
$('#messagetext').val('').focus();
});
});
});
</script>
</body>
</html>
Time to run the application; press F5. I would suggest selecting Internet Explorer with debug.
![img3.jpg]()
Image 3.
As you can see, two windows open; one for HTML content and the second asks for a name. Copy the browser URL and paste in another browser window then provide a name and click "OK".
Now copy that URL into another window.
![img4.jpg]()
Image 4.
Now provide another name to that TextBox and click "OK".
So don't get confused; provide a different name to windows like this.
![img5.jpg]()
Image 5.
Now type a message from the first window and respond from another window.
![img6.jpg]()
Image 6.
As you will see, both windows are loading messages without delaying on their name that we provided.