UIElement.CaptureMouse 方法

定义

命名空间:

System.Windows

程序集:

PresentationCore.dll

尝试将鼠标强制捕获到此元素。

public:
 virtual bool CaptureMouse();

public bool CaptureMouse ();

abstract member CaptureMouse : unit -> bool
override this.CaptureMouse : unit -> bool

Public Function CaptureMouse () As Boolean

返回

Boolean

如果成功捕获了鼠标，则为 true；否则为 false。

实现

CaptureMouse()

示例

以下示例为鼠标和键输入组合实现一对处理程序，这些处理程序捕获 (和取消捕获) 鼠标，并启用用于查看 3D 模型的特殊鼠标模式。

private void MouseDownHandler(object sender, MouseButtonEventArgs e)
{
    if (!Enabled) return;
    e.Handled = true;

    if (Keyboard.IsKeyDown(Key.F1))
    {
        Reset();
        return;
    }

    UIElement el = (UIElement)sender;
    _point = e.MouseDevice.GetPosition(el);
    // Initialize the center of rotation to the lookatpoint
    if (!_centered)
    {
        ProjectionCamera camera = (ProjectionCamera)_slaves[0].Camera;
        _center = camera.LookDirection;
        _centered = true;
    }

    _scaling = (e.MiddleButton == MouseButtonState.Pressed);

    if (!Keyboard.IsKeyDown(Key.Space))
        _rotating = true;
    else
        _rotating = false;

    el.CaptureMouse();
}

private void MouseUpHandler(object sender, MouseButtonEventArgs e)
{
    if (!_enabled) return;
    e.Handled = true;

    // Stuff the current initial + delta into initial so when we next move we
    // start at the right place.
    if (_rotating)
    {
        _rotation = _rotationDelta * _rotation;
    }
    else
    {
        _translate += _translateDelta;
        _translateDelta.X = 0;
        _translateDelta.Y = 0;
    }

    //_scale = _scaleDelta*_scale;
    UIElement el = (UIElement)sender;
    el.ReleaseMouseCapture();
}

Private Sub MouseDownHandler(ByVal sender As Object, ByVal e As MouseButtonEventArgs)
    If Not Enabled Then
        Return
    End If
    e.Handled = True


    If Keyboard.IsKeyDown(Key.F1) = True Then
        Reset()
        Return
    End If

    Dim el As UIElement = CType(sender, UIElement)
    _point = e.MouseDevice.GetPosition(el)
    ' Initialize the center of rotation to the lookatpoint
    If Not _centered Then
        Dim camera As ProjectionCamera = CType(_slaves(0).Camera, ProjectionCamera)
        _center = camera.LookDirection
        _centered = True
    End If

    _scaling = (e.MiddleButton = MouseButtonState.Pressed)

    If Keyboard.IsKeyDown(Key.Space) = False Then
        _rotating = True
    Else
        _rotating = False
    End If

    el.CaptureMouse()
End Sub

Private Sub MouseUpHandler(ByVal sender As Object, ByVal e As MouseButtonEventArgs)
    If Not _enabled Then
        Return
    End If
    e.Handled = True

    ' Stuff the current initial + delta into initial so when we next move we
    ' start at the right place.
    If _rotating = True Then
        _rotation = _rotationDelta * _rotation
    Else
        _translate += _translateDelta
        _translateDelta.X = 0
        _translateDelta.Y = 0
    End If

    '_scale = _scaleDelta * _scale
    Dim el As UIElement = CType(sender, UIElement)
    el.ReleaseMouseCapture()
End Sub

注解

若要捕获，必须启用 元素。 在调用 CaptureMouse之前检查是否IsEnabled为 true 。

如果调用 CaptureMouse 返回 true，则 IsMouseCaptured 也是 true。

如果调用 CaptureMouse 返回 ，则GotMouseCapture引发 和 IsMouseCapturedChanged 事件，在RoutedEventArgs.Source事件中，数据报告为调用 方法的CaptureMouse元素。true 如果强制捕获，可能会干扰现有捕获 - 尤其是与使用鼠标拖放相关的捕获。

若要从所有元素中清除鼠标捕获，请使用 提供的参数调用 Mouse.Captureelementnull。

另请参阅

• IsMouseCaptured