completed the branch

src/Shared/HandyControl_Shared/Controls/Slider/CompareSlider/CompareSlider.cs

@@ -0,0 +1,26 @@
+using System.Windows;
+using System.Windows.Controls;
+
+namespace HandyControl.Controls
+{
+    public class CompareSlider : Slider
+    {
+        public static readonly DependencyProperty TargetContentProperty = DependencyProperty.Register(
+            "TargetContent", typeof(object), typeof(CompareSlider), new PropertyMetadata(default(object)));
+
+        public static readonly DependencyProperty SourceContentProperty = DependencyProperty.Register(
+            "SourceContent", typeof(object), typeof(CompareSlider), new PropertyMetadata(default(object)));
+
+        public object TargetContent
+        {
+            get => GetValue(TargetContentProperty);
+            set => SetValue(TargetContentProperty, value);
+        }
+
+        public object SourceContent
+        {
+            get => GetValue(SourceContentProperty);
+            set => SetValue(SourceContentProperty, value);
+        }        
+    }
+}