在控制台应用程序中动态创建并导出WPF Viewport3D可视化对象

Question

我正在开发一个WPF用户控件库中的WPF用户控件，它使用Viewport3D。

在运行应用程序时，我可以在视口中看到图像，并且如果我在 WPF应用程序 中调用RenderTargetBitmap，我可以将其保存到文件中。

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图像，则保存空图像。 代码如下：

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);
        }
    }

}

在控制台应用程序中，加载事件未被触发，viewport3D_Loaded也未被处理，因此我需要手动调用。

有没有一种方法可以在内存中加载可视化内容并以编程方式呈现到文件中？

- Onur Gazioğlu

Answer 1

我需要在“takeScreenshot”方法中实例化“bmp”之后添加此委托

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

- Onur Gazioğlu