UIElement.CaptureMouse Method

Definition

Attempts to force capture of the mouse to this element.

C#
public bool CaptureMouse();

Returns

true if the mouse is successfully captured; otherwise, false.

Implements

Examples

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.

C#
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();
}

Remarks

To be captured, an element must be enabled. Check whether IsEnabled is true before you call CaptureMouse.

If calling CaptureMouse returns true, then IsMouseCaptured is also true.

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. If you force capture, you might interfere with existing captures - especially with captures that relate to drag-and-drop with the mouse.

To clear mouse capture from all elements, call Mouse.Capture with the element parameter provided as null.

Applies to

Product Versions
.NET Framework 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
Windows Desktop 3.0, 3.1, 5, 6, 7, 8, 9

See also