Execute a delegate in the ui thread (using message pump)

Question

I have a background thread that handles communication with an external service. Each time the background thread receives a message I\'d like to pass it to the UI thread for

Answer 1

Here is an example of using the Dispacther object in WPF with MSMQ.

The code behind:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Messaging;

namespace MSMQGui
{
    /// 

    /// Interaction logic for MainWindow.xaml
    /// 
    public partial class MainWindow : Window
    {
        private string queueName = @".\private$\MyFunWithMSMQ";
        private MessageQueue queue = null;

        public MainWindow()
        {
            InitializeComponent();

            if (!MessageQueue.Exists(queueName))
                MessageQueue.Create(queueName,false);


           queue = new MessageQueue(queueName);
           queue.ReceiveCompleted += receiveCompleted;

        }

        private void btnAddMessage_Click(object sender, RoutedEventArgs e)
        {
            string message = txtMessage.Text;
            txtMessage.Text = String.Empty;

            queue.Send(message);

            MessageBox.Show("Message :" + message + " sent");
        }

        private void Populate(object sender, RoutedEventArgs e)
        {
            try
            {
                queue.BeginReceive(TimeSpan.FromSeconds(1)) ;     
            }
            catch (MessageQueueException)
            {
                MessageBox.Show("No message available");
            }
        }

        private void receiveCompleted(object source, ReceiveCompletedEventArgs e)
        {
            try
            {
                var message=queue.EndReceive(e.AsyncResult);



                Action addMessage= (string msg) => {
                     ListViewItem item = new ListViewItem();
                     item.Content = msg;
                     lsvMessages.Items.Add(item);
                };

                this.Dispatcher.Invoke(addMessage, message.Body as string);
            }
            catch (MessageQueueException)
            {
                MessageBox.Show("No message available");
            }
        }
    }
}

The XAML: