UIElement.CaptureMouse 方法

定义

尝试将鼠标强制捕获到此元素。Attempts to force capture of the mouse to this element.

public:
 virtual bool CaptureMouse();
public bool CaptureMouse ();
abstract member CaptureMouse : unit -> bool
override this.CaptureMouse : unit -> bool
Public Function CaptureMouse () As Boolean

返回

如果成功捕获了鼠标,则为 true;否则为 falsetrue if the mouse is successfully captured; otherwise, false.

实现

示例

下面的示例实现了一对鼠标和键输入组合的处理程序,这些处理程序用于捕获(和 uncapture)鼠标,并为查看3D 模型启用了特殊的鼠标模式。The following example implements a pair of handlers for mouse and key input combination that capture (and uncapture) the mouse and enable a special mouse mode for viewing a 3D model.

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


    if (Keyboard.IsKeyDown(Key.F1) == true)
    {
        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) == false)
        _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 == true)
        _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,必须启用一个元素。To be captured, an element must be enabled. 在调用 CaptureMouse之前,请检查是否 true IsEnabledCheck whether IsEnabled is true before you call CaptureMouse.

如果调用 CaptureMouse 将返回 true,则 IsMouseCapturedtrueIf calling CaptureMouse returns true, then IsMouseCaptured is also true.

如果调用 CaptureMouse 返回 true,则将引发 GotMouseCaptureIsMouseCapturedChanged 事件,并在事件数据中将 RoutedEventArgs.Source 报告为调用 CaptureMouse 方法的元素。If calling CaptureMouse returns true, then the GotMouseCapture and IsMouseCapturedChanged events are raised, with RoutedEventArgs.Source in the event data reported as the element where the CaptureMouse method is called. 如果强制捕获,则可能会干扰现有捕获,尤其是与用鼠标拖放相关的捕获。If you force capture, you might interfere with existing captures - especially with captures that relate to drag-and-drop with the mouse.

若要从所有元素中清除鼠标捕获,请用 null提供的 element 参数调用 Mouse.CaptureTo clear mouse capture from all elements, call Mouse.Capture with the element parameter provided as null.

适用于

另请参阅