WPF - 如何将控件的位置绑定到当前鼠标位置？

Question

有没有办法绑定到XAML文件中的WPF中的鼠标位置？或者这必须在代码中完成吗？我在Canvas中有一个控件,我只想让控件在鼠标光标位于Canvas中时跟随鼠标.

谢谢

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编辑:

好吧,我认为使用代码隐藏文件相对简单.我在Canvas上添加了一个MouseMove事件处理程序,然后添加:

    private void Canvas_MouseMove(object sender, MouseEventArgs e)
    {
        // Get the x and y coordinates of the mouse pointer.
        System.Windows.Point position = e.GetPosition(this);
        double pX = position.X;
        double pY = position.Y;

        // Sets the position of the image to the mouse coordinates.
        myMouseImage.SetValue(Canvas.LeftProperty, pX);
        myMouseImage.SetValue(Canvas.TopProperty, pY);
    }

使用http://msdn.microsoft.com/en-us/library/ms746626.aspx作为指导.

Answer 1

我试图为此目的制作一种装饰器.您将对象,鼠标位置包裹在您想要控制的位置上,并将某些控件绑定到装饰器MousePosition属性.

public class MouseTrackerDecorator : Decorator
{
    static readonly DependencyProperty MousePositionProperty;
    static MouseTrackerDecorator()
    {
        MousePositionProperty = DependencyProperty.Register("MousePosition", typeof(Point), typeof(MouseTrackerDecorator));
    }

    public override UIElement Child
    {
        get
        {
            return base.Child;
        }
        set
        {
            if (base.Child != null)
                base.Child.MouseMove -= _controlledObject_MouseMove;
            base.Child = value;
            base.Child.MouseMove += _controlledObject_MouseMove;
        }
    }

    public Point MousePosition
    {
        get
        {
            return (Point)GetValue(MouseTrackerDecorator.MousePositionProperty);
        }
        set
        {
            SetValue(MouseTrackerDecorator.MousePositionProperty, value);
        }
    }

    void _controlledObject_MouseMove(object sender, MouseEventArgs e)
    {
        Point p = e.GetPosition(base.Child);

        // Here you can add some validation logic
        MousePosition = p;            
    }
}

和XAML

<local:MouseTrackerDecorator x:Name="mouseTracker">
    <Canvas Width="200" Height="200" Background="Red">
        <Button Width="20" Height="20" Canvas.Left="{Binding ElementName=mouseTracker, Path=MousePosition.X}" Canvas.Top="{Binding ElementName=mouseTracker, Path=MousePosition.Y}"  />
    </Canvas>
</local:MouseTrackerDecorator>