public override async Task ExecuteAsync(object parameter)
{
await m_semaphore.WaitAsync();
m_cancelCommand.NotifyCommandStarting();
Execution = new TaskCompletionNotifier <TResult>(action(parameter, m_cancelCommand.CancelToken));
Execution.Run();
TaskCompletionNotifier <TResult> me = Execution;
RaiseCanExecuteChanged();
m_semaphore.Release();
await Execution.TaskCompletion;
await m_semaphore.WaitAsync();
if (me == Execution)
{
m_cancelCommand.NotifyCommandCompleted();
RaiseCanExecuteChanged();
}
m_semaphore.Release();
}
public object Convert(object value, Type targetType, object parameter, string language)
{
//var image = value as Image;
//if (image == null || image.BaseUri == null)
//{
// var bitmap = new BitmapImage(new Uri("ms-appx:///Assets/www/news_detail_header_def.jpg"));
// var notifier = new TaskCompletionNotifier<BitmapImage>();
// notifier.SetTask(Task.FromResult(bitmap));
// return notifier;
//}
//else
//{
// var task = Task.Run(async () =>
// {
// var cache = ServiceLocator.Current.GetInstance<ImageCache>();
// var uri = await cache.GetImageSourceFromUrlAsync(image.BaseUri.ToString());
// return uri;
// });
// var notifier = new TaskCompletionNotifier<BitmapImage>();
// notifier.SetTask(task, c => new BitmapImage(c));
// return notifier;
//}
if (value != null)
{
var task = Task.Run(async() =>
{
var cache = ImageCache.CreateInstance();
var uri = await cache.GetImageSourceFromUrlAsync(value.ToString());
return(uri);
});
var notifier = new TaskCompletionNotifier <BitmapImage>();
notifier.SetTask(task, c => new BitmapImage(c));
return(notifier);
}
else
{
return(string.Empty);
}
}
