NullReferenceException在WPF中为vtk加载RenderWindowControl

Question

我正在尝试使用ActiViz.NET和Visual Studio 2013从我的WPF项目中的vtk库加载RenderWindowControl.该库工作正常,因为我做了一个新项目只是为了练习但是当我尝试将它集成到我的工作中时,我得到了这次是一个null RenderWindowControl.这是我的代码:

MainWindow.xaml:

<Window x:Class="myProject.Views.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
    xmlns:VtkTab="clr-namespace:myProject.Views.UITabs.VtkTab"
    x:Name="Mainwindow"
    MinHeight="600"
    MinWidth="800"
    Title="{Binding Title}"
    Height="720"
    Width="1280"
    Icon="{StaticResource ApplicationIcon}"
    Loaded="OnLoaded"
    DataContext="{Binding Main, Source={StaticResource ViewModelLocator}}"
    Style="{StaticResource WindowStyle}"
    mc:Ignorable="d">

    <DockPanel>
        <TabControl>
        ....
        ....
        <VtkTab:VtkTabView />
        ....
        .... 
        </TabControl>
    </DockPanel>
</Window>

VtkTabView.xaml:

<UserControl x:Class="myProject.Views.UITabs.VtkTab.VtkTabView"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:vtk="clr-namespace:Kitware.VTK;assembly=Kitware.VTK"
        Loaded="WindowLoaded"
        Height="480" Width="640">
        <WindowsFormsHost Name="Wfh">
            <vtk:RenderWindowControl x:Name="RenderControl" />
        </WindowsFormsHost>
</UserControl>

VtkTabView.xaml.cs:

public partial class UITabView
{

    protected static Random _random = new Random();
    vtkActor actor = vtkActor.New();

    public VtkTabView()
    {
        InitializeComponent();

        var sphere = vtkSphereSource.New();
        sphere.SetThetaResolution(8);
        sphere.SetPhiResolution(16);

        var shrink = vtkShrinkPolyData.New();
        shrink.SetInputConnection(sphere.GetOutputPort());
        shrink.SetShrinkFactor(0.9);

        var move = vtkTransform.New();
        move.Translate(_random.NextDouble(), _random.NextDouble(), _random.NextDouble());
        var moveFilter = vtkTransformPolyDataFilter.New();
        moveFilter.SetTransform(move);

        moveFilter.SetInputConnection(shrink.GetOutputPort());

        var mapper = vtkPolyDataMapper.New();
        mapper.SetInputConnection(moveFilter.GetOutputPort());

        // The actor links the data pipeline to the rendering subsystem 
        actor.SetMapper(mapper);
        actor.GetProperty().SetColor(1, 0, 0);
    }

    private void WindowLoaded(object sender, RoutedEventArgs e)
    {
        var renderer = RenderControl.RenderWindow.GetRenderers().GetFirstRenderer();
        renderer.AddActor(actor);
    }
}

WindowLoaded(VtkTabView.xaml.cs)上的RenderControl.RenderWindow为null,我不知道为什么.可能是因为我从第二个xamp加载UITabView并且我丢失了RenderControl的内容？这是我看到的唯一区别与我做的例子相比.

Answer 1

访问RenderWindowControl的RenderWindow on Load事件.

例如

public VtkTabView()
{
    InitializeComponent();
    // initialize your sphrere and actor

    RenderControl.Load += MyRenderWindowControlOnLoad;
}

private void MyRenderWindowControlOnLoad(object sender_in, EventArgs eventArgs_in){

//access the RenderWindow here

}