/// <summary>
 /// 将<paramref name="uploadingImageFile"/>从<see cref="UploadingImageFiles"/>中去除
 /// </summary>
 /// <param name="uploadingImageFile"></param>
 public void RemoveFile(UploadingImageFile uploadingImageFile)
 {
     if (uploadingImageFile == null)
     {
         return;
     }
     UploadingImageFiles.Remove(uploadingImageFile);
 }
 /// <summary>
 /// 将选择的文件添加到<see cref="UploadingImageFiles"/>
 /// </summary>
 /// <param name="readOnlyList"></param>
 public void AddFiles(IReadOnlyList <StorageFile> readOnlyList)
 {
     if (readOnlyList == null)
     {
         return;
     }
     foreach (var file in readOnlyList)
     {
         UploadingImageFiles.Add(new UploadingImageFile(file, SourceActivity.Name));
     }
 }