/// <summary>
        /// 下载文件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void Load(object sender, RoutedEventArgs e)
        {
            ObservableCollection <FileEntity> fileList = fileListbox.ItemsSource as ObservableCollection <FileEntity>;

            if (fileList != null)
            {
                foreach (var fileEntity in fileList)
                {
                    if (fileEntity.IsFile && fileEntity.IsChecked)
                    {
                        long fileSize = 1;
                        long.TryParse(fileEntity.FileSize, out fileSize);
                        //未拿到文件长度的,之后要进行特殊处理
                        _detailViewModel.Load(fileEntity.FileId, fileEntity.FileName, fileSize);
                    }
                }
            }
        }