崇拜者和装饰元素事件

问题描述:

我有一个自定义的线条形状,该线条使用装饰物在该行的中间显示一个数组和一些文本。

I have a custom Line Shape that use an adorner to display an array and some text in the middle of that line.

问题是装饰的行为独立于装饰元素,并且确实而不是将事件转移给它。在下面的代码中,我被迫手动将adorner元素重新链接到装饰元素( ta.MouseLeftButtonDown + = Adorner_MouseLeftButtonDown; ),但不幸的是,这甚至无法正常工作...
有人可以告诉我调用this.OnMouseLeftButtonDown的问题是什么,为什么我没有收到相应的事件?

The problem is that the adorned behaves independently of the adorned element, and does not "transfer" the event to it. In the following code I am forced to manually relink the adorner elements to adorned element (ta.MouseLeftButtonDown += Adorner_MouseLeftButtonDown;), but unfortunately even this does not work... Could somebody advice what is wrong when calling this.OnMouseLeftButtonDown, why I don't receive the respective event?

public class SegmentLine : Shape
{
    AdornerLayer aLayer;

    public static readonly DependencyProperty X1Property;
    public static readonly DependencyProperty X2Property;
    public static readonly DependencyProperty Y1Property;
    public static readonly DependencyProperty Y2Property;
    ...

    static SegmentLine() {
        X1Property = DependencyProperty.Register("X1", typeof(double), typeof(SegmentLine), new FrameworkPropertyMetadata(double.NaN,
            FrameworkPropertyMetadataOptions.AffectsRender));
        X2Pro...
    }

    public SegmentLine()
        : base()
    {
        this.Loaded += SegmentLine_Loaded;
    }

    void SegmentLine_Loaded(object sender, RoutedEventArgs e)
    {
        aLayer = AdornerLayer.GetAdornerLayer(this);
        if (aLayer != null)
        {
            TextAdorner ta = new TextAdorner(this);
            //ta.IsHitTestVisible = false;
            ta.MouseLeftButtonDown += Adorner_MouseLeftButtonDown;
            aLayer.Add(ta);
        }
    }

    void Adorner_MouseLeftButtonDown(object sender, System.Windows.Input.MouseButtonEventArgs e)
    {
        // !! try to rise the MouseLeftButtonDown event
        this.OnMouseLeftButtonDown(e);
    }

    protected override void OnRender(DrawingContext drawingContext)
    {
        base.OnRender(drawingContext);
        if (aLayer != null)
            aLayer.Update();
    }

    class TextAdorner : Adorner
    {
        public TextAdorner(UIElement adornedElement)
            : base(adornedElement) { }

        protected override void OnRender(DrawingContext drawingContext)
        {
            // ADD LABEL ...
            FormattedText ft = new FormattedText(...);
            drawingContext.DrawText(ft, midPoint);

            // Add ARROW ...
            var myPathGeometry = new PathGeometry { Figures = myPathFigureCollection };            
            drawingContext.DrawGeometry(Brushes.Black, null, myPathGeometry);
        }
    }

    protected override System.Windows.Media.Geometry DefiningGeometry
    {
        get
        {
            var geometryGroup = new GeometryGroup();
            // Add line
            geometryGroup.Children.Add(new LineGeometry(new Point(X1, Y1), new Point(X2, Y2)));
            return geometryGroup;
        }
    }    
}


您应该调用 this.RaiseEvent(e); 而不是 this.OnMouseLeftButtonDown(e); 将事件转移到装饰元素。

而且,您只能使用一个事件处理程序来转移几种事件类型

You should call this.RaiseEvent(e); instead of this.OnMouseLeftButtonDown(e); to transfer the event to the adorned element.
And by the way, you can use only one event handler to transfer several event types

void SegmentLine_Loaded(object sender, RoutedEventArgs e)
{
    ..
    ta.MouseLeftButtonDown += Adorner_AnyEvent;
    ta.MouseRightButtonDown += Adorner_AnyEvent;
}

void Adorner_AnyEvent(object sender, RoutedEventArgs e)
{
    this.RaiseEvent(e);
}