support for .NET framework 3.5

Still have bugs

Net35/HandyControl_Net35/Tools/Converter/Boolean2BooleanReConverter.cs

@@ -0,0 +1,27 @@
+using System;
+using System.Globalization;
+using System.Windows.Data;
+
+namespace HandyControl.Tools.Converter
+{
+    public class Boolean2BooleanReConverter : IValueConverter
+    {
+        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            if (value is bool boolValue)
+            {
+                return !boolValue;
+            }
+            return value;
+        }
+
+        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            if (value is bool boolValue)
+            {
+                return !boolValue;
+            }
+            return value;
+        }
+    }
+}