wpf 装饰类

可以通过装饰类给现有控件添加显示效果

装饰类需要继承Adorner

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

        //重写渲染
        protected override void OnRender(DrawingContext drawingContext)
        {
            //Rect adornedElementRect = new Rect(this.AdornedElement.DesiredSize);

            Rect adornedElementRect = new Rect(this.AdornedElement.RenderSize);

            // Some arbitrary drawing implements.
            SolidColorBrush renderBrush = new SolidColorBrush(Colors.Green);
            renderBrush.Opacity = 0.2;
            Pen renderPen = new Pen(new SolidColorBrush(Colors.Navy), 1.5);
            double renderRadius = 5.0;

            // Draw a circle at each corner.
            drawingContext.DrawEllipse(renderBrush, renderPen, adornedElementRect.TopLeft, renderRadius, renderRadius);
            drawingContext.DrawEllipse(renderBrush, renderPen, adornedElementRect.TopRight, renderRadius, renderRadius);
            drawingContext.DrawEllipse(renderBrush, renderPen, adornedElementRect.BottomLeft, renderRadius, renderRadius);
            drawingContext.DrawEllipse(renderBrush, renderPen, adornedElementRect.BottomRight, renderRadius, renderRadius);
        }
    }

调用

var layer = AdornerLayer.GetAdornerLayer(addAdorner);
layer.Add(new MoveRotateAdorner(addAdorner));