private static Task PerformDispatcherQueueAction(DispatcherQueueHandler action)
{
try
{
action();
return(Task.CompletedTask);
}
catch (Exception exc)
{
return(Task.FromException(exc));
}
}
private static void PerformDispatcherQueueAction(TaskCompletionSource taskCompletionSource, DispatcherQueueHandler action)
{
try
{
action();
taskCompletionSource.SetResult();
}
catch (Exception exc)
{
taskCompletionSource.SetException(exc);
}
}
/// <summary>
/// Runs the specified task on the thread associated with the <see cref="DispatcherQueue"/>
/// with the specified priority asynchronously.
/// </summary>
/// <param name="dispatcher">The <see cref="DispatcherQueue"/> with which the thread is associated.</param>
/// <param name="priority">The priority of the task (such as Low, Normal, or High).</param>
/// <param name="action">The delegate to the task to execute.</param>
/// <returns>A task that represents the asynchronous operation.</returns>
public static Task RunAsync(this DispatcherQueue dispatcher, DispatcherQueuePriority priority, DispatcherQueueHandler action)
{
if (dispatcher.HasThreadAccess)
{
return(PerformDispatcherQueueAction(action));
}
var taskCompletionSource = new TaskCompletionSource();
if (!dispatcher.TryEnqueue(priority, () => PerformDispatcherQueueAction(taskCompletionSource, action)))
{
taskCompletionSource.SetException(new InvalidOperationException("Failed to enqueue the task to execute."));
}
return(taskCompletionSource.Task);
}
/// <summary> /// Runs the specified task on the thread associated with the <see cref="DispatcherQueue"/> asynchronously. /// </summary> /// <param name="dispatcher">The <see cref="DispatcherQueue"/> with which the thread is associated.</param> /// <param name="action">The delegate to the task to execute.</param> /// <returns>A task that represents the asynchronous operation.</returns> public static Task RunAsync(this DispatcherQueue dispatcher, DispatcherQueueHandler action) => RunAsync(dispatcher, DispatcherQueuePriority.Normal, action);
