Question

我正在使用Viewport3D的wpf用户控件库中开发一个wpf用户控件。

我在运行应用程序的viewport中看到图像，如果我在 WPF应用程序中调用它，我可以使用RenderTargetBitmap将其保存到文件中。

但是，如果我在控制台应用程序中实例化用户控件并尝试导出，则保存空图像。代码是

class Program
{
    static void Main(string[] args)
    {
        Thread t = new Thread(DoIt);
        t.SetApartmentState(ApartmentState.STA);
        t.Start();
        Console.WriteLine("press enter");
        Console.ReadLine();
    }
    static void DoIt()
    {
        var x = new WpfControlLibrary1.Showcase();

        x.GenerateViewPort();
        x.TakeScreenshot(300, 300);
    }
}

public partial class Showcase : UserControl
{
    private PerspectiveCamera _PerspectiveCamera = null;

    public Showcase()
    {
        InitializeComponent();
        this.Loaded += new RoutedEventHandler((sender, e) => this.GenerateViewPort());
    }

    public void GenerateViewPort()
    {
        this._PerspectiveCamera = new PerspectiveCamera(new Point3D(0, 0, 5), new Vector3D(0, 0, -5), new Vector3D(0, 1, 0), 45);

        var viewport3D = new Viewport3D() { Camera = this._PerspectiveCamera };
        viewport3D.Children.Add(new ModelVisual3D() { Content = GenerateModel() });
        viewport3D.Loaded += new RoutedEventHandler(this.viewport3D_Loaded);
        this.grdAniContainer.Children.Add(viewport3D);
    }

    private static Model3DGroup GenerateModel()
    {
        ...
    }

    void viewport3D_Loaded(object sender, RoutedEventArgs e)
    {
        ...
    }

    public void TakeScreenshot(int width, int height)
    {
        takeScreenshot(this.grdAniContainer.Children[0], width, height);
    }

    private static void takeScreenshot(Visual visual, int width, int height)
    {
        var v = visual as Viewport3D;
        v.Width = width;
        v.Height = height;
        v.Measure(new Size(width, height));
        v.Arrange(new Rect(0, 0, width, height));


        var vRect = new Rectangle();
        vRect.Width = width;
        vRect.Height = height;
        vRect.Fill = Brushes.White;
        vRect.Arrange(new Rect(0, 0, vRect.Width, vRect.Height));

        var bmp = new RenderTargetBitmap(width, height, 96, 96, PixelFormats.Pbgra32);
        bmp.Render(vRect);
        bmp.Render(v);

        var png = new PngBitmapEncoder();
        png.Frames.Add(BitmapFrame.Create(bmp));

        var dlg = new SaveFileDialog();
        dlg.DefaultExt = ".png";
        dlg.Filter = "PNG Images (.png)|*.png";
        if (dlg.ShowDialog() ?? false == true)
        {
            string filepath = dlg.FileName;
            using (var stm = File.Create(filepath))
                png.Save(stm);
        }
    }

}

未触发加载事件且控制台应用程序中未处理viewport3D_Loaded，因此我手动调用。

有没有办法在内存中加载视觉效果并以编程方式呈现文件？

Answer 1

我需要在“takeScreenshot”方法

中实例化“bmp”后添加此委托

v.Dispatcher.Invoke(((Action)(() => bmp.Render(v))), DispatcherPriority.Render);

以编程方式在控制台应用程序中动态创建和导出WPF Viewport3D可视对象

1 个答案: