WpF 控件截图

 private void CreateImage()

        {

            FileStream fs = new FileStream("image.png", FileMode.Create);

            RenderTargetBitmap bmp = new RenderTargetBitmap((int)bt.ActualWidth,

                                                           (int)bt.ActualHeight, 100, 100,

                                                          PixelFormats.Pbgra32);

            bmp.Render(this.bt );

            BitmapEncoder encoder = new PngBitmapEncoder();



            encoder.Frames.Add(BitmapFrame.Create(bmp));

            encoder.Save(fs);

            fs.Dispose();

            Close();

            fs.Dispose();





        }