没有画布作为根的Silverlight自定义鼠标光标?

你不能逃避使用画布,但这并不意味着你必须遵守画布如何安排事情。

我创造了一些对你有用的行为。

第一种是:

[TypeConstraint(typeof(Canvas))]
public class MouseCursorAction : TargetedTriggerAction<UIElement>
{

    protected override void Invoke(object parameter)
    {
    }

    protected override void OnAttached()
    {
        var canvas = AssociatedObject as Canvas;
        if (canvas == null) { return; }
        canvas.MouseMove += new MouseEventHandler(canvas_MouseMove);
        canvas.MouseEnter += new MouseEventHandler(canvas_MouseEnter);
        canvas.MouseLeave += new MouseEventHandler(canvas_MouseLeave);
    }

    void canvas_MouseLeave(object sender, MouseEventArgs e)
    {
        Target.Visibility = Visibility.Collapsed;
    }

    void canvas_MouseEnter(object sender, MouseEventArgs e)
    {
        Target.Visibility = Visibility.Visible;
    }

    void canvas_MouseMove(object sender, MouseEventArgs e)
    {
        var canvas = sender as Canvas;
        var positionInCanvas = e.GetPosition(canvas);
        Canvas.SetTop(Target, positionInCanvas.Y);
        Canvas.SetLeft(Target, positionInCanvas.X);
    }
}

通过这种行为,您可以转换鼠标光标中的任何UIElement。只需将其设置为画布并选择鼠标光标所需的目标。

现在,为了解决布局问题,我创建了另一个行为:

[TypeConstraint(typeof(Canvas))]
public class FillCanvasAction : TargetedTriggerAction<FrameworkElement>
{

    protected override void Invoke(object parameter)
    {
    }

    protected override void OnAttached()
    {
        var canvas = AssociatedObject as Canvas;
        if (canvas == null) { return; }
        canvas.SizeChanged += new SizeChangedEventHandler(Target_SizeChanged);
    }

    void Target_SizeChanged(object sender, SizeChangedEventArgs e)
    {
        var element = Target;
        if (element == null) { return; }

        var canvas = sender as Canvas;

        element.Width = canvas.ActualWidth;
        element.Height = canvas.ActualHeight;
        Canvas.SetTop(element, 0);
        Canvas.SetLeft(element, 0);
    }
}

当附加到父画布时,此行为会将目标FrameworkElement(例如网格)的大小调整为父画布的大小。这意味着您可以在这个FrameworkElement中创建自己的自定义布局,而不必担心Canvas处理布局的方式。

<Grid x:Name="LayoutRoot" Cursor="None">
    <Canvas x:Name="canvas" Background="Black">
        <i:Interaction.Triggers>
            <i:EventTrigger EventName="MouseEnter">
                <local:MouseCursorAction TargetObject="{Binding ElementName=cursorImage}"/>
            </i:EventTrigger>
            <i:EventTrigger>
                <local:FillCanvasAction TargetObject="{Binding ElementName=grid}"/>
            </i:EventTrigger>
        </i:Interaction.Triggers>
        <Grid x:Name="grid" Background="White" Width="600" Height="400">
            <!-- Create your layout here -->
        </Grid>
        <Image x:Name="cursorImage" Height="50" Width="50" Source="mouse_cursor.png"/>
    </Canvas>
</Grid>

你可以从 here

免责声明:严格来说,应该使用弱事件处理来实现此行为,以避免内存泄漏;但是,该实现超出了此答案的范围。你可以在这个网站上找到更多关于弱事件处理的信息,以及你的项目是否需要它。