support for .NET framework 3.5

Still have bugs

Net35/HandyControl_Net35/Controls/Slider/CompareSlider.cs

@@ -0,0 +1,59 @@
+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);
+        }
+
+        //private bool _isLoaded;
+
+        //private double _tempValue;
+
+        //public CompareSlider()
+        //{
+        //    //Loaded += delegate
+        //    //{
+        //    //    if (_isLoaded) return;
+        //    //    _isLoaded = true;
+        //    //    Value = _tempValue;
+        //    //};
+        //}
+
+        ////protected override void OnRender(DrawingContext drawingContext)
+        ////{
+        ////    base.OnRender(drawingContext);
+
+        ////    Value = _tempValue;
+        ////}
+
+        ////public override void OnApplyTemplate()
+        ////{
+        ////    base.OnApplyTemplate();
+        ////    _tempValue = Value;
+        ////    Value = Orientation == Orientation.Horizontal ? Maximum : 0;
+        ////    if (_isLoaded)
+        ////    {
+        ////        Value = _tempValue;
+        ////    }
+        ////}
+    }
+}