鼠标移动比重绘 wpf 快

mouse move is faster than redraw wpf

我正在定义继承自 class Shape 的形状并实现 'Geometry' 属性.

这是一个例子:

public class Landmark : Shape
{
    public override bool IsInBounds(Point currentLocation)
    {

        return (((currentLocation.X >= Location.X - 3) && (currentLocation.X <= Location.X + 3)) && ((currentLocation.Y >= Location.Y - 3) && (currentLocation.Y <= Location.Y + 3)));
    }

    protected override Geometry DefiningGeometry
    {
        get
        {
            var landMark = new EllipseGeometry {Center = Location};

            Stroke = Brushes.Red;
            return landMark;
        }
    }

    protected override void OnIsMouseDirectlyOverChanged(DependencyPropertyChangedEventArgs e)
    {
        StrokeThickness = IsMouseDirectlyOver ? 12 : 6;
        Mouse.OverrideCursor = IsMouseDirectlyOver ? Mouse.OverrideCursor = Cursors.ScrollAll : Mouse.OverrideCursor = Cursors.Arrow;
    }
    protected override void OnMouseMove(MouseEventArgs e)
    {
        if (e.LeftButton == MouseButtonState.Pressed)
        {
            Location = e.GetPosition(this);
            InvalidateVisual();
        }
    }
}

当我点击 Shape 并移动鼠标时,我希望 Shape 在新位置重新绘制 - 它确实有效。

但是,如果我快速移动鼠标 "too",那么我就是 "leaving" OnMouseMove 事件,并且 shape 卡在最后一个位置鼠标指针和 Shape 的位置在 "sync".

这样的问题能解决吗?

是的,by capturing the Mouse

为此,您必须确定何时捕获以及何时释放。由于您希望它与鼠标左键一起使用,因此您可以在 OnMouseDown 中捕获并在 OnMouseUp 中释放鼠标。