‘Control.InvokeRequired’ is one of the mostly used functions in developing muti-threaded GUIs in .NET Framework. While developing a sample application for Vista, I wanted to use the same functionality but new WPF controls living in System.Windows.Controls namespace don’t have ‘InvokeRequired’ (similarly don’t have Invoke and BeginInvoke methods as WPF Controls do not implement ISynchronizeInvoke interface). So, what’s the solution? WPF introduces two new classes DispatcherObject and Dispatcher. They provide the functionality to manipulate your WPF controls from other threads safely. As an example, the following code snippet in .NET framework 1.0 – 2.0:

private void UpdateMyButton()
        {
            if (!this.button1.InvokeRequired)
            {
                //I’m on the GUI thread!
                //Safe to update my ‘button1′ properties
                button1.Text = “Updated”;

            }
            else
            {
                //Synchronize my access!
                button1.BeginInvoke(new UpdateGUIDelegate(UpdateMyButton));

            }

}

 should be replaced with this one if you’re using WPF controls in .NET Framework 3.0:

private void UpdateMyWPFButton()
        {
            if (this.button1.CheckAccess())
            {
                this.button1.Content = “Updated!”;
            }
            else
            {
                this.button1.Dispatcher.BeginInvoke(System.Windows.Threading.DispatcherPriority.Normal, new UpdateDelegate(this.UpdateMyWPFButton));
            }
}