Winform中调用Wpf用户控件的键盘预览

我有一个Winform应用程序，我从中调用Wpf Usercontrol，它实际上是一个Viewport3D，Winform应用程序在其上绘制3D元素，例如圆柱体

我需要从Winform应用程序访问键盘，以便捕捉用于放大/缩小的^+和^-按键，以及用于旋转显示器的箭头键

基本代码如下所示。键盘控制处理程序在Sub New中定义。虽然mouseControl工作正常，但Form1从未接收到键盘笔划。在Form1中启用键盘预览

有人有什么建议吗

提前谢谢。克劳德

        Private Sub Form1_Load(sender As System.Object, _
                               e      As System.EventArgs) Handles MyBase.Load 


        ' Create the WPF UserControl.
        '
        WpfUc        = New UserControl1
        ' ==========================

        Host.Dock =  DockStyle.Fill
        Host.Name = "Host"


        ' Assign the WPF UserControl to the ElementHost control's
        ' Child property.
        '
        Host.Child = WpfUc      


        ' Add the ElementHost control to the form's
        ' collection of child controls.
        '
        Me.Controls.Add(Host)


        Visual3d            = New ModelVisual3D
        Group3d             = New Model3DGroup

     
        Visual3d.Content      = Group3d
        WpfUc.myViewport.Children.Add(Visual3d)


        DefineCamera(TheCamera, WpfUC.myViewport)
        DefineModelCylinders(Group3d)
    End Sub

    Private Sub DefineCamera(ByRef iCamera     As OrthographicCamera,          _
                             ByRef viewport    As Windows.Controls.Viewport3D)

        iCamera                   = New OrthographicCamera
        CameraController          = New SphericalCameraController(iCamera, viewport, WpfUc, WpfUc, WpfUc)
        iCamera.FarPlaneDistance  = 100
        iCamera.NearPlaneDistance = 0
        iCamera.Position          = New Point3D(0, 0, 100)
        iCamera.Width             = 15

    End Sub

    Friend Sub New(ByVal Camera          As OrthographicCamera,           _
                   ByVal viewport        As Windows.Controls.Viewport3D,  _
                   ByVal keyboardControl As UIElement,                    _
                   ByVal wheelControl    As UIElement,                    _
                   ByVal mouseControl    As UIElement)

        TheCamera                   = Camera
        viewport.Camera             = TheCamera

        iKeyboardControl            = keyboardControl
        AddHandler KeyboardControl.PreviewKeyDown,      AddressOf KeyboardControl_KeyDown

        iWheelControl               = wheelControl
        AddHandler WheelControl.PreviewMouseWheel,      AddressOf WheelControl_PreviewMouseWheel

        iMouseControl               = mouseControl
        AddHandler iMouseControl.MouseDown,             AddressOf MouseControl_MouseDown

        PositionCamera()

    End Sub

  Private Sub KeyboardControl_KeyDown(ByVal sender As Object, _
                                      ByVal e      As KeyEventArgs)

        Select Case e.Key
            Case Key.Up
                IncreasePhi()
            Case Key.Down
                DecreasePhi()
            Case Key.Left
                IncreaseTheta()
            Case Key.Right
                DecreaseTheta()
            Case Key.Add, Key.OemPlus
                IncreaseR()
            Case Key.Subtract, Key.OemMinus
                DecreaseR()
        End Select

        PositionCamera()
    End Sub

Wpf用户控件出现在下面

<UserControl
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="d" x:Class="HostingWpfUserControlInWf.UserControl1"
    d:DesignWidth="477.396" d:DesignHeight="274.41"
    >
   <Grid Margin="0">
      <!-- Viewport3D is the rendering surface. -->
      <Viewport3D x:Name="myViewport" x:FieldModifier="Public" Margin="0,0,0,0">
      </Viewport3D>
   </Grid>
</UserControl>

---

好吧，经过大量的研究和反复试验，我发现要将键盘输入传递到托管表单，需要Wpf Usercontrol的两个设置：

    WpfUc.Focusable = True

    WpfUC.myViewport.Focusable = True

很容易，但很难找到