public void Invoke(Windows.UI.Core.DispatchedHandler handler)
{
// Validate argument.
if (handler == null)
{
throw new NullReferenceException("handler");
}
// Invoke the given handler on the main UI thread now. (This is a block call.)
System.Windows.Threading.Dispatcher dispatcher = System.Windows.Deployment.Current.Dispatcher;
if (dispatcher.CheckAccess())
{
handler.Invoke();
}
else if (sIsDispatcherValid)
{
var waitEvent = new System.Threading.AutoResetEvent(false);
var operation = dispatcher.BeginInvoke(() =>
{
handler.Invoke();
waitEvent.Set();
});
waitEvent.WaitOne();
}
}
/// <summary>
/// Allows updating a view model property from a non-UI thread. An example would be running
/// a task in a thread-pool thread that downloads data the view model needs. Once downloaded
/// the UI property needs to be updated; however, you cannot access UI elements from a non UI
/// thread so you marshal it over using this function which calls the Window Dispatcher to run
/// the given task.
///
/// Use example:
/// InvokeOnUIThread(() => { DelayedAchievementCount = result; });
///
/// </summary>
/// <param name="task">
/// The task to update the desired property
/// </param>
protected void InvokeOnUIThread(Windows.UI.Core.DispatchedHandler task)
{
if (_syncContext != null && _syncContext != SynchronizationContext.Current)
{
_syncContext.Post(delegate { task.Invoke(); }, null);
}
else
{
task.Invoke();
}
}
public static async Task EnsureOnAsync(Windows.UI.Core.DispatchedHandler callback)
{
if (App.Dispatcher.HasThreadAccess)
{
callback.Invoke();
}
else
{
await App.Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, callback);
}
}
private void RunOnMainThread(Windows.UI.Core.DispatchedHandler handler)
{
if (Dispatcher.HasThreadAccess)
{
handler.Invoke();
}
else
{
// Note: use a discard "_" to silence CS4014 warning
_ = Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, handler);
}
}
public static Task RunOnMainThread(Windows.UI.Core.DispatchedHandler handler)
{
var dispatcher = Windows.ApplicationModel.Core.CoreApplication.MainView.CoreWindow.Dispatcher;
if (dispatcher.HasThreadAccess)
{
handler.Invoke();
return(Task.CompletedTask);
}
else
{
return(dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, handler).AsTask());
}
}
