replace v6 with experimental v7 code

src/MpvNet.Windows/WPF/HandyControl/Controls/Attach/IconElement.cs

@@ -0,0 +1,36 @@
+
+using System.Windows;
+using System.Windows.Media;
+
+namespace HandyControl.Controls
+{
+    public class IconElement
+    {
+        public static readonly DependencyProperty GeometryProperty = DependencyProperty.RegisterAttached(
+            "Geometry", typeof(Geometry), typeof(IconElement), new PropertyMetadata(default(Geometry)));
+
+        public static void SetGeometry(DependencyObject element, Geometry value)
+            => element.SetValue(GeometryProperty, value);
+
+        public static Geometry GetGeometry(DependencyObject element)
+            => (Geometry) element.GetValue(GeometryProperty);
+
+        public static readonly DependencyProperty WidthProperty = DependencyProperty.RegisterAttached(
+            "Width", typeof(double), typeof(IconElement), new PropertyMetadata(double.NaN));
+
+        public static void SetWidth(DependencyObject element, double value)
+            => element.SetValue(WidthProperty, value);
+
+        public static double GetWidth(DependencyObject element)
+            => (double) element.GetValue(WidthProperty);
+
+        public static readonly DependencyProperty HeightProperty = DependencyProperty.RegisterAttached(
+            "Height", typeof(double), typeof(IconElement), new PropertyMetadata(double.NaN));
+
+        public static void SetHeight(DependencyObject element, double value)
+            => element.SetValue(HeightProperty, value);
+
+        public static double GetHeight(DependencyObject element)
+            => (double) element.GetValue(HeightProperty);
+    }
+}