wpf - 将大的 WPF Canvas 切成许多小的 PNG 图像

Question

假设我有非常大的 (3000 X 4000) WPF Canvas 。

我正在寻找将此 Canvas 分割成一堆 n x n .png 图像 block 的最佳方法。

有什么建议吗？

Answer 1

不确定最好还是最简单，但这里有一个方法 :)

private void SaveFrameworkElement(FrameworkElement frameworkElement)
{
    BitmapImage bitmapImage = VisualToBitmapImage(frameworkElement);
    for (int startX = 0; startX <= 400; startX += 100)
    {
        for (int startY = 0; startY <= 100; startY += 100)
        {
            SaveImage(bitmapImage, startX, startY, 100, 100, "C:\\CutImage_" + startX.ToString() + "-" + startY.ToString() + ".png");
        }
    }
}

public BitmapImage VisualToBitmapImage(FrameworkElement frameworkElement)
{
    RenderTargetBitmap rtb = new RenderTargetBitmap((int)frameworkElement.ActualWidth,
                                                    (int)frameworkElement.ActualHeight,
                                                    96d,
                                                    96d,
                                                    PixelFormats.Default);
    rtb.Render(frameworkElement);

    MemoryStream stream = new MemoryStream();
    PngBitmapEncoder encoder = new PngBitmapEncoder();
    encoder.Frames.Add(BitmapFrame.Create(rtb));
    encoder.Save(stream);

    BitmapImage bitmapImage = new BitmapImage();
    bitmapImage.BeginInit();
    bitmapImage.StreamSource = stream;
    bitmapImage.EndInit();

    return bitmapImage;            
}
public void SaveImage(BitmapImage sourceImage,
                      int startX,
                      int startY,
                      int width,
                      int height,
                      string filePath)
{
    TransformGroup transformGroup = new TransformGroup();
    TranslateTransform translateTransform = new TranslateTransform();
    translateTransform.X = -startX;
    translateTransform.Y = -startY;
    transformGroup.Children.Add(translateTransform);

    DrawingVisual vis = new DrawingVisual();
    DrawingContext cont = vis.RenderOpen();
    cont.PushTransform(transformGroup);
    cont.DrawImage(sourceImage, new Rect(new Size(sourceImage.PixelWidth, sourceImage.PixelHeight)));
    cont.Close();

    RenderTargetBitmap rtb = new RenderTargetBitmap(width, height, 96d, 96d, PixelFormats.Default);
    rtb.Render(vis);

    FileStream stream = new FileStream(filePath, FileMode.Create);
    PngBitmapEncoder encoder = new PngBitmapEncoder();
    encoder.Frames.Add(BitmapFrame.Create(rtb));
    encoder.Save(stream);
    stream.Close();
}