请问怎么保存WPF里Path.Data的图形到png文件？

Question

Path.Data里是GeometryGroup包裹的PathGeometry，有办法把这个图案保存到文件吗？

Answer 1

你可以参照下面的代码来使用DrawingContext.DrawGeometry方法来保存你的GeometryGroup到图片文件。
Xaml:

<Grid x:Name="myGrid">
        
        <Path x:Name="myPath" Stroke="Black" StrokeThickness="1" StrokeLineJoin="Round" StrokeMiterLimit="1" Width="64" Height="64" Fill="Yellow" VerticalAlignment="Top" HorizontalAlignment="Left" ClipToBounds="True">
            <Path.Data>
                <GeometryGroup x:Name="group" >
                    <EllipseGeometry x:Name="e1" Center="32,32" RadiusX="32" RadiusY="32"/>
                    <PathGeometry x:Name="g1" Figures="M 32,32 L 32,16 M 32,32 L 16,32 M 32,32 L 16,16 Z"/>
                </GeometryGroup>
            </Path.Data>
        </Path>
        <Button x:Name="btngetimage"  Content="GetImage" Width="100" Height="30" Click="btngetimage_Click" HorizontalAlignment="Center"></Button>

        
    </Grid>

后台的代码：

private void btngetimage_Click(object sender, RoutedEventArgs e)
        {
            RenderTargetBitmap bmp = new RenderTargetBitmap(500, 500, 96, 96, PixelFormats.Default);
            DrawingVisual viz = new DrawingVisual();
            using (DrawingContext dc = viz.RenderOpen()) 
            {
                dc.DrawGeometry(myPath.Fill, new Pen(myPath.Stroke, myPath.StrokeThickness), group);
            }
            bmp.Render(viz);
            PngBitmapEncoder pngEncoder = new PngBitmapEncoder();
            pngEncoder.Frames.Add(BitmapFrame.Create(bmp));
            using (FileStream file = new FileStream("test.png", FileMode.Create))
                pngEncoder.Save(file);
        }

最终的效果图：