LocalMessageReceiver.Listen Method
Microsoft Silverlight will reach end of support after October 2021. Learn more.
Starts listening for messages from a LocalMessageSender.
Namespace: System.Windows.Messaging
Assembly: System.Windows (in System.Windows.dll)
Syntax
'Declaration
<SecuritySafeCriticalAttribute> _
Public Sub Listen
[SecuritySafeCriticalAttribute]
public void Listen()
Exceptions
| Exception | Condition |
|---|---|
| InvalidOperationException | The Listen method has already been called. |
| ObjectDisposedException | The Dispose method has already been called. |
| ListenFailedException | There is already a receiver registered with the same name and name scope. |
Remarks
This method registers the LocalMessageReceiver and enables it to receive messages.
After you call this method, the MessageReceived event will occur when a LocalMessageSender configured to send messages to this receiver calls its SendAsync method.
To stop receiving messages, you must call the Dispose method.
For more information, see Communication Between Local Silverlight-Based Applications.
Examples
The following code example demonstrates how to use this method. This example is part of a larger example available in How to: Implement Communication Between Local Silverlight-Based Applications.
Imports System
Imports System.Windows.Controls
Imports System.Windows.Messaging
Partial Public Class Receiver
Inherits UserControl
Public Sub New()
InitializeComponent()
Dim messageReceiver As New LocalMessageReceiver("receiver", _
ReceiverNameScope.Global, LocalMessageReceiver.AnyDomain)
AddHandler messageReceiver.MessageReceived, _
AddressOf messageReceiver_MessageReceived
Try
messageReceiver.Listen()
Catch ex As ListenFailedException
output.Text = "Cannot receive messages." & Environment.NewLine & _
"There is already a receiver with the name 'receiver'."
End Try
End Sub
Private Sub messageReceiver_MessageReceived( _
ByVal sender As Object, ByVal e As MessageReceivedEventArgs)
e.Response = "response to " & e.Message
output.Text = _
"Message: " & e.Message & Environment.NewLine & _
"NameScope: " & e.NameScope.ToString() & Environment.NewLine & _
"ReceiverName: " & e.ReceiverName & Environment.NewLine & _
"SenderDomain: " & e.SenderDomain & Environment.NewLine & _
"Response: " & e.Response
End Sub
End Class
using System;
using System.Windows.Controls;
using System.Windows.Messaging;
namespace ReceivingApplication
{
public partial class Receiver : UserControl
{
public Receiver()
{
InitializeComponent();
LocalMessageReceiver messageReceiver =
new LocalMessageReceiver("receiver",
ReceiverNameScope.Global, LocalMessageReceiver.AnyDomain);
messageReceiver.MessageReceived += messageReceiver_MessageReceived;
try
{
messageReceiver.Listen();
}
catch (ListenFailedException)
{
output.Text = "Cannot receive messages." + Environment.NewLine +
"There is already a receiver with the name 'receiver'.";
}
}
private void messageReceiver_MessageReceived(
object sender, MessageReceivedEventArgs e)
{
e.Response = "response to " + e.Message;
output.Text =
"Message: " + e.Message + Environment.NewLine +
"NameScope: " + e.NameScope + Environment.NewLine +
"ReceiverName: " + e.ReceiverName + Environment.NewLine +
"SenderDomain: " + e.SenderDomain + Environment.NewLine +
"Response: " + e.Response;
}
}
}
Version Information
Silverlight
Supported in: 5, 4, 3
Platforms
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.