private void Client_UploadFileCompleted(object sender, UploadFileCompletedEventLibArgs e)
 {
     if (e.TransmissionState == TransmissionState.Success)
     {
         _uploadSuccess   = true;
         _uploadException = null;
     }
     else
     {
         _uploadException = e.WebException;
         Trace.WriteLine("上传失败");
     }
 }
 private void _helper_UploadFileCompleted(object sender, UploadFileCompletedEventLibArgs e)
 {
     UploadFileCompleted?.Invoke(sender, e);
 }