private void RemoveDownloadTask(DownloadImageTask downloadTask)
{
lock (this.DownloadTasks)
{
this.DownloadTasks.Remove(downloadTask.TileIndex);
}
}
public Task <BitmapSource> LoadTileAsync(TileIndex.Full index, IProgress <double> progress, CancellationToken cancellationToken)
{
if (!this.DownloadTasks.TryGetValue(index, out var downloadTask) ||
!downloadTask.Status.IsAlive())
{
var url = this.GetTileAddress(index);
downloadTask = new DownloadImageTask(this, index, url);
lock (this.DownloadTasks)
{
this.DownloadTasks.Add(index, downloadTask);
}
}
downloadTask.HandleObserver(progress, cancellationToken);
return(downloadTask.CompletionSource.Task);
}
