#78 Add to obtain the current angle

 Add to obtain the current angle #78

Author: yanjinhuagood

src/WPFDevelopers.Samples.Shared/Controls/ElementAdorner/ElementAdorner.cs

@@ -1,5 +1,6 @@
 using System;
 using System.ComponentModel;
+using System.Diagnostics;
 using System.Windows;
 using System.Windows.Controls;
 using System.Windows.Controls.Primitives;
@@ -14,6 +15,29 @@ namespace WPFDevelopers.Samples.Controls
 {
     public class ElementAdorner : Adorner
     {
+        public event RoutedPropertyChangedEventHandler<double> AngleChanged;
+
+        protected virtual void OnAngleChanged(double oldValue, double newValue)
+        {
+            RoutedPropertyChangedEventArgs<double> args = new RoutedPropertyChangedEventArgs<double>(oldValue, newValue);
+            AngleChanged?.Invoke(this, args);
+        }
+
+        private double angle;
+        public double Angle
+        {
+            get { return angle; }
+            set
+            {
+                if (angle != value)
+                {
+                    double oldValue = angle;
+                    angle = value;
+                    OnAngleChanged(oldValue, angle);
+                }
+            }
+        }
+
         private const double ThumbSize = 16, ElementMiniSize = 20;
         private const double RotateThumbSize = 20;
         private readonly Thumb tLeft;
@@ -244,7 +268,7 @@ private Thumb CreateRotateThumb()
             return thumb;
         }
 
-       
+        
         private Brush GetFactoryRotate()
         {
             var lan =
@@ -262,9 +286,8 @@ private void Thumb_DragDelta(object sender, DragDeltaEventArgs e)
             {
                 var currentPoint = Mouse.GetPosition(canvas);
                 var deltaVector = Point.Subtract(currentPoint, centerPoint);
-
                 var angle = Vector.AngleBetween(startVector, deltaVector);
-
+                Angle = angle;
                 var rotateTransform = designerItem.RenderTransform as RotateTransform;
                 rotateTransform.Angle = initialAngle + Math.Round(angle, 0);
                 designerItem.InvalidateMeasure();
@@ -293,9 +316,7 @@ private void Thumb_DragStarted(object sender, DragStartedEventArgs e)
                     initialAngle = 0;
                 }
                 else
-                {
                     initialAngle = rotateTransform.Angle;
-                }
             }
         }
     }

src/WPFDevelopers.Samples.Shared/Controls/ElementAdorner/TransformThumb.cs

@@ -1,11 +1,24 @@
 using System.Windows;
 using System.Windows.Controls;
 using System.Windows.Documents;
+using System.Xml.Linq;
 
 namespace WPFDevelopers.Samples.Controls
 {
     public class TransformThumb : ContentControl
     {
+        public double Angle
+        {
+            get { return (double)GetValue(AngleProperty); }
+            set { SetValue(AngleProperty, value); }
+        }
+        public static readonly DependencyProperty AngleProperty =
+            DependencyProperty.Register("Angle", typeof(double), typeof(TransformThumb), new PropertyMetadata(0d, OnAngleChanged));
+
+        private static void OnAngleChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
+        {
+           
+        }
         static TransformThumb()
         {
             DefaultStyleKeyProperty.OverrideMetadata(typeof(TransformThumb), new FrameworkPropertyMetadata(typeof(TransformThumb)));
@@ -21,10 +34,23 @@ void CreateAdorner()
             var adornerLayer = AdornerLayer.GetAdornerLayer(this);
             if (adornerLayer != null)
             {
+                var adorners = adornerLayer.GetAdorners(this);
+                if (adorners != null)
+                    foreach (var item in adorners)
+                        if (item is ElementAdorner container)
+                            adornerLayer.Remove(container);
                 var adorner = new ElementAdorner(this);
+                adorner.AngleChanged -= Adorner_AngleChanged;
+                adorner.AngleChanged += Adorner_AngleChanged;
                 adornerLayer.Add(adorner);
             }
         }
+
+        private void Adorner_AngleChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
+        {
+            Angle = e.NewValue;
+        }
+
         private void TransformThumb_IsVisibleChanged(object sender, DependencyPropertyChangedEventArgs e)
         {
             if (e.NewValue is bool isVisible)

src/WPFDevelopers.Samples.Shared/ExampleViews/TransformThumbExample.xaml

@@ -27,13 +27,15 @@
                 Canvas.Left="305"
                 Canvas.Top="205"
                 Width="280"
-                Height="100">
+                Height="100" x:Name="MyTransformThumb">
                 <TextBlock
                     HorizontalAlignment="Center"
                     VerticalAlignment="Center"
                     FontSize="40"
-                    Foreground="White"
-                    Text="WPF开发者" />
+                    Foreground="White">
+                    <Run>WPF开发者</Run>
+                    <Run Text="{Binding ElementName=MyTransformThumb,Path=Angle,StringFormat=0.00}"></Run>
+                </TextBlock>
             </controls:TransformThumb>
             <controls:TransformThumb
                 Canvas.Left="100"