如何从ScrollViewer中的图像捕获画布区域

// 获取ScrollViewer的可视区域大小和位置
double scrollViewerWidth = scrollViewer.ActualWidth;
double scrollViewerHeight = scrollViewer.ActualHeight;
double scrollViewerHorizontalOffset = scrollViewer.HorizontalOffset;
double scrollViewerVerticalOffset = scrollViewer.VerticalOffset;

// 创建RenderTargetBitmap对象
RenderTargetBitmap renderTargetBitmap = new RenderTargetBitmap((int)scrollViewerWidth, (int)scrollViewerHeight, 96, 96, PixelFormats.Pbgra32);

// 渲染ScrollViewer的内容到RenderTargetBitmap
renderTargetBitmap.Render(scrollViewer);

// 将RenderTargetBitmap转换为BitmapImage
BitmapImage bitmapImage = new BitmapImage();
bitmapImage.BeginInit();
bitmapImage.StreamSource = new MemoryStream();
BitmapEncoder encoder = new PngBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(renderTargetBitmap));
encoder.Save(bitmapImage.StreamSource);
bitmapImage.EndInit();

// 在Image控件中显示捕获的图像
image.Source = bitmapImage;