Imports System
Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Messaging

Partial Public Class Sender
    Inherits UserControl

    Private messageSender As LocalMessageSender

    Public Sub New()

        InitializeComponent()
        UpdateButton()
        messageSender = New LocalMessageSender( _
            "receiver", LocalMessageSender.Global)
        AddHandler messageSender.SendCompleted, _
            AddressOf sender_SendCompleted
        SendMessage("message from Sender constructor")

    End Sub

    Private clickNumber As Integer = 1

    Private Sub UpdateButton()
        button.Content = "send message 'click " & clickNumber & "'"
    End Sub

    Private Sub Button_Click(ByVal sender As Object, _
        ByVal e As RoutedEventArgs)

        SendMessage("click " & clickNumber)
        clickNumber += 1
        UpdateButton()

    End Sub

    Private Const MAX_ATTEMPTS As Integer = 10000
    Private attempt As Integer = 1

    Private Sub SendMessage(ByVal message As String)
        messageSender.SendAsync(message, attempt)
    End Sub

    Private Sub sender_SendCompleted(ByVal sender As Object, _
        ByVal e As SendCompletedEventArgs)

        If e.Error IsNot Nothing Then

            LogError(e)
            attempt += 1
            If attempt > MAX_ATTEMPTS Then
                output.Text = "Could not send message."
                Return
            End If
            SendMessage(e.Message)
            Return

        End If

        output.Text = _
            "Message: " & e.Message & Environment.NewLine & _
            "Attempt " & CType(e.UserState, Integer) & _
            " completed." & Environment.NewLine & _
            "Response: " & e.Response & Environment.NewLine & _
            "ReceiverName: " & e.ReceiverName & Environment.NewLine & _
            "ReceiverDomain: " & e.ReceiverDomain

        ' Reset attempt counter.
        attempt = 1

    End Sub

    Private Sub LogError(ByVal e As SendCompletedEventArgs)
        System.Diagnostics.Debug.WriteLine( _
            "Attempt number {0}: {1}: {2}", CType(e.UserState, Integer), _
            e.Error.GetType().ToString(), e.Error.Message)
    End Sub

End Class

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Messaging;

namespace SendingApplication
{
    public partial class Sender : UserControl
    {
        private LocalMessageSender messageSender;

        public Sender()
        {
            InitializeComponent();
            UpdateButton();
            messageSender = new LocalMessageSender(
                "receiver", LocalMessageSender.Global);
            messageSender.SendCompleted += sender_SendCompleted;
            SendMessage("message from Sender constructor");
        }

        private int clickNumber = 1;

        private void UpdateButton()
        {
            button.Content = "send message 'click " + clickNumber + "'";
        }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            SendMessage("click " + clickNumber);
            clickNumber++;
            UpdateButton();
        }

        private const int MAX_ATTEMPTS = 10000;
        private int attempt = 1;

        private void SendMessage(string message)
        {
            messageSender.SendAsync(message, attempt);
        }

        private void sender_SendCompleted(object sender, SendCompletedEventArgs e)
        {
            if (e.Error != null)
            {
                LogError(e);
                attempt++;
                if (attempt > MAX_ATTEMPTS)
                {
                    output.Text = "Could not send message.";
                    return;
                }
                SendMessage(e.Message);
                return;
            }

            output.Text =
                "Message: " + e.Message + Environment.NewLine +
                "Attempt " + (int)e.UserState + 
                " completed." + Environment.NewLine +
                "Response: " + e.Response + Environment.NewLine +
                "ReceiverName: " + e.ReceiverName + Environment.NewLine + 
                "ReceiverDomain: " + e.ReceiverDomain;

            // Reset attempt counter.
            attempt = 1;
        }

        private void LogError(SendCompletedEventArgs e)
        {
            System.Diagnostics.Debug.WriteLine(
                "Attempt number {0}: {1}: {2}", (int)e.UserState, 
                e.Error.GetType().ToString(), e.Error.Message);
        }

    }
}