StorageClient UploadObjectAsync定期引发异常TaskwasCancelled

Question

我正在使用Google Storage Client上传文件。

但是，它从不上传。 突然，此抛出异常始终为TaskCanceledException。  甚至CancellationTokenSource也从未取消。

IProgress<IUploadProgress> UploadProgress = new Progress<IUploadProgress>(OnUploadProgress);

using (FileStream fileStream = File.OpenRead(localpath))
{

    if (null != await StorageClient.UploadObjectAsync(bucketname, objectname, null, fileStream, null, CancellationTokenSource.Token, UploadProgress))
    { 
        result = true;
    }
}

private void OnUploadProgress(IUploadProgress googleProgress)
{
    case Google.Apis.Upload.UploadStatus.Failed:
    {
        //always come inside this...
        googleProgress.Exception is TaskCanceledException
    }

    break;
}