MVVM Light Threading Example

Question

Are there any examples on how to use the Threading portion of MVVM Light? What is the advantage of using the MVVMLight.threading over normal .net threading?

Answer 1

looks like all threading portion in mvvmlight is this class :

public static class DispatcherHelper
{

    public static Dispatcher UIDispatcher
    {
        get;
        private set;
    }

    /// <summary>
    /// Executes an action on the UI thread. If this method is called
    /// from the UI thread, the action is executed immendiately. If the
    /// method is called from another thread, the action will be enqueued
    /// on the UI thread's dispatcher and executed asynchronously.
    /// <para>For additional operations on the UI thread, you can get a
    /// reference to the UI thread's dispatcher thanks to the property
    /// <see cref="UIDispatcher" /></para>.
    /// </summary>
    /// <param name="action">The action that will be executed on the UI
    /// thread.</param>
    public static void CheckBeginInvokeOnUI(Action action)
    {
        if (UIDispatcher.CheckAccess())
        {
            action();
        }
        else
        {
            UIDispatcher.BeginInvoke(action);
        }
    }

    /// <summary>
    /// This method should be called once on the UI thread to ensure that
    /// the <see cref="UIDispatcher" /> property is initialized.
    /// <para>In a Silverlight application, call this method in the
    /// Application_Startup event handler, after the MainPage is constructed.</para>
    /// <para>In WPF, call this method on the static App() constructor.</para>
    /// </summary>
    public static void Initialize()
    {
        if (UIDispatcher != null)
        {
            return;
        }

        // for silverlight
        UIDispatcher = Deployment.Current.Dispatcher;

        // wpf
        //IDispatcher = Dispatcher.CurrentDispatcher;

    }
}

}

and that's all. Use DispatcherHelper.Initialize() according to comment in static App constructor (wpf) or Application_Startup event handler (Silverlight) - and then u can use DispatcherHelper.CheckBeginInvokeOnUI(Action action)

Regards