public class ResizingAdorner : Adorner
{
Thumb topLeft;
// To store and manage the adorner's visual children.
VisualCollection visualChildren;
// Initialize the ResizingAdorner.
public ResizingAdorner(UIElement adornedElement)
: base(adornedElement)
{
visualChildren = new VisualCollection(this);
// Call a helper method to initialize the Thumbs
BuildAdornerCorner(ref topLeft, Cursors.SizeNWSE);
//these are events for the thumbs you may want it or not according to your needs//
topLeft.PreviewMouseLeftButtonDown += new MouseButtonEventHandler(topLeft_PreviewMouseLeftButtonDown);
topLeft.DragDelta += new DragDeltaEventHandler(HandleTopLeft);
}
//override this method for rendering
protected override void OnRender(DrawingContext drawingContext)
{
Rect adornedElementRect = new Rect(this.AdornedElement.DesiredSize);
// Some arbitrary drawing implements.
SolidColorBrush RectBrush = new SolidColorBrush(Colors.Green);
RectBrush.Opacity = 0.3;
Pen renderPen = new Pen(RectBrush, 1.5);
// Draw Rectangle
drawingContext.DrawRectangle(null, renderPen, adornedElementRect);
}
// Arrange the Adorners.
protected override Size ArrangeOverride(Size finalSize)
{
Rect adornedElementRect = new Rect(this.AdornedElement.DesiredSize);
// desiredWidth and desiredHeight are the width and height of the element that's being adorned.
// These will be used to place the ResizingAdorner at the corners of the adorned element.
double desiredWidth = adornedElementRect.BottomRight.X;
double desiredHeight = adornedElementRect.BottomRight.Y;
// adornerWidth & adornerHeight are used for placement as well.
double adornerWidth = adornedElementRect.TopLeft.X;
double adornerHeight = adornedElementRect.TopLeft.Y;
//Arrange PathPoints with the helper Methods
topLeft.Arrange(new Rect(new Point(adornerWidth, adornerHeight), new Point(desiredWidth, desiredHeight)));
// Return the final size.
return finalSize;
}
// set some appearance properties, and add the elements to the visual tree//
void BuildAdornerCorner(ref Thumb cornerThumb, Cursor customizedCursor)
{
Path adornered = AdornedElement as Path;
if (cornerThumb != null) return;
cornerThumb = new Thumb();
// Set some arbitrary visual characteristics.
cornerThumb.Cursor = customizedCursor;
cornerThumb.Height = cornerThumb.Width = 10;
cornerThumb.Opacity = 1;
cornerThumb.Background = new SolidColorBrush(Colors.Black);
visualChildren.Add(cornerThumb);
}
// UnScale Adorners. this part is optional
public override GeneralTransform GetDesiredTransform(GeneralTransform transform)
{
if (this.visualChildren != null)
{
foreach (var thumb in this.visualChildren.OfType<Thumb>())
{
thumb.RenderTransform
= new ScaleTransform(1 / ScaleXC, 1 / ScaleYC);
thumb.RenderTransformOrigin = new Point(0.5, 0.5);
}
}
return base.GetDesiredTransform(transform);
}
}
之后使用如下所示的这个类来装饰元素
AdornerLayer ADL; //consider this is as a public field somewhere in your class
...
...
ResizingAdorner A = new XamlEditor.ResizingAdorner(p); // p is an UIElement I my case
ADL = AdornerLayer.GetAdornerLayer(p);
ADL.Add(A);
1 回答
首先，你需要创建一个派生自Adorner的类，如下所示 . 您可以使用拇指或拇指进行渲染 . 这里是我之前实现过的代码，但为了简单起见我稍微改了一些，所以可能会有错误 .
之后使用如下所示的这个类来装饰元素