将DrawingImage转换为BitmapImage

我想绘制大量的形状（线条，椭圆和……），然后将它们保存为位图或png。 我制作了图纸，问题是：如何在C＃ 中将DrawingImage转换为BitmapImage ？ 代码是这样的：

DrawingGroup drawingGroup = new DrawingGroup(); using(DrawingContext context = drawingGroup.Open()) { //make some drawing } DrawingImage drawingImage = new DrawingImage(drawingGroup) // your suggestion? DrawingImage - > BitmapImage 

Answer 1

您可以将ImageDrawing放入Image控件并将其渲染为RenderTargetBitmap ，这是一个BitmapSource，因此可以通过BitmapEncoder （本例中为PngBitmapEncoder）进行序列化。

 public void SaveDrawingToFile(Drawing drawing, string fileName, double scale) { var drawingImage = new Image { Source = new DrawingImage(drawing) }; var width = drawing.Bounds.Width * scale; var height = drawing.Bounds.Height * scale; drawingImage.Arrange(new Rect(0, 0, width, height)); var bitmap = new RenderTargetBitmap((int)width, (int)height, 96, 96, PixelFormats.Pbgra32); bitmap.Render(drawingImage); var encoder = new PngBitmapEncoder(); encoder.Frames.Add(BitmapFrame.Create(bitmap)); using (var stream = new FileStream(fileName, FileMode.Create)) { encoder.Save(stream); } } 

请注意，实际上并不需要BitmapImage进行编码，因为BitmapSource（或RenderTargetBitmap等任何派生类）将被接受为BitmapFrame.Create的参数。

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稍微不同的解决方案将涉及DrawingVisual而不是DrawingImage：

 public void SaveDrawingToFile(Drawing drawing, string fileName, double scale) { var drawingVisual = new DrawingVisual(); using (var drawingContext = drawingVisual.RenderOpen()) { drawingContext.PushTransform(new ScaleTransform(scale, scale)); drawingContext.PushTransform(new TranslateTransform(-drawing.Bounds.X, -drawing.Bounds.Y)); drawingContext.DrawDrawing(drawing); } var width = drawing.Bounds.Width * scale; var height = drawing.Bounds.Height * scale; var bitmap = new RenderTargetBitmap((int)width, (int)height, 96, 96, PixelFormats.Pbgra32); bitmap.Render(drawingVisual); var encoder = new PngBitmapEncoder(); encoder.Frames.Add(BitmapFrame.Create(bitmap)); using (var stream = new FileStream(fileName, FileMode.Create)) { encoder.Save(stream); } }