TemplatedAdorner.cs

using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Media;
 
namespace Vereinsmeisterschaften.Behaviors
{
    public class TemplatedAdorner : Adorner
    {
        private ContentPresenter _contentPresenter;
 
        #region Constructor

        public TemplatedAdorner(UIElement adornedElement, DataTemplate contentDataTemplate, object content) : base(adornedElement)
        {
            _contentPresenter = new ContentPresenter
            {
                ContentTemplate = contentDataTemplate,
                Content = content,
                DataContext = content
            };
 
            AdornerLayer adornerLayer = AdornerLayer.GetAdornerLayer(AdornedElement);
            adornerLayer?.Add(this);
        }
 
        #endregion
 
        // ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 
        #region Overridden
 
        protected override int VisualChildrenCount => 1;
 
        protected override Visual GetVisualChild(int index) => this._contentPresenter;
 
        protected override Size MeasureOverride(Size constraint) => this.AdornedElement.RenderSize;
 
        protected override Size ArrangeOverride(Size finalSize)
        {
            _contentPresenter.Arrange(new Rect(new Point(0, 0), finalSize));
            return finalSize;
        }
 
        #endregion
    }
}