BitmapImage.EndInit() throwing 'System.NotSupportedExcep

这是我的代码：我在这里用这段代码填充 MemoryStream。

private void treeView_MouseDoubleClick(object sender, MouseButtonEventArgs e)
    {
        try
        {
            var a = treeView.SelectedItem as TreeViewItem;
            if (a.Header.ToString().EndsWith(".jpg"))
            {
                Bitmap temp = new Bitmap(a.Tag.ToString());
                try
                {
                    OriginalImage.Dispose();  
                }
                catch { };
                OriginalImage = new MemoryStream(); 
                temp.Save(OriginalImage, ImageFormat.Bmp);                    
                Uri path = new Uri(a.Tag.ToString());
                actualImage.Source = new BitmapImage(path);
            }
        }
        catch { };
    }

就在那个块之后，这应该会发生，但在"位图"上。EndInit（）" 我得到异常'系统.不支持异常"。

 var bitmap = new BitmapImage();                
 bitmap.BeginInit();
 bitmap.StreamSource = OriginalImage;
 bitmap.CacheOption = BitmapCacheOption.OnLoad;
 bitmap.EndInit();
 bitmap.Freeze();    
 actualImage.Source = bitmap;

有人知道可能是什么原因造成的吗？这些方法假设在System.Windows.Controls.Image中加载图像，第二个块是在编辑图片之前将加载的图像返回到其默认值。

NotSupportedException.StackTrace 是：

"at System.Windows.Media.Imaging.BitmapDecoder.SetupDecoderFromUriOrStream(Uri uri, Stream stream, BitmapCacheOption cacheOption, Guid& clsId, Boolean& isOriginalWritable, Stream& uriStream, UnmanagedMemoryStream& unmanagedMemoryStream, SafeFileHandle& safeFilehandle)'r'n   at System.Windows.Media.Imaging.BitmapDecoder.CreateFromUriOrStream(Uri baseUri, Uri uri, Stream stream, BitmapCreateOptions createOptions, BitmapCacheOption cacheOption, RequestCachePolicy uriCachePolicy, Boolean insertInDecoderCache)'r'n   at System.Windows.Media.Imaging.BitmapImage.FinalizeCreation()'r'n   at System.Windows.Media.Imaging.BitmapImage.EndInit()'r'n   at WpfApplication2.MainWindow.resetBtn_Click(Object sender, RoutedEventArgs e) in c:''Users''Albert Sato Damas''Desktop''ImageEditing - Copy - Copy''WpfApplication2''MainWindow.xaml.cs:line 270"

inputImageStream.Position = 0;