support for .NET framework 3.5

Still have bugs

Net35/HandyControl_Net35/Controls/Other/Shield.cs

@@ -0,0 +1,38 @@
+using System.Windows;
+using System.Windows.Controls.Primitives;
+using System.Windows.Markup;
+using System.Windows.Media;
+
+namespace HandyControl.Controls
+{
+    [ContentProperty(nameof(Status))]
+    public class Shield : ButtonBase
+    {
+        public static readonly DependencyProperty SubjectProperty = DependencyProperty.Register(
+            "Subject", typeof(string), typeof(Shield), new PropertyMetadata(default(string)));
+
+        public string Subject
+        {
+            get => (string) GetValue(SubjectProperty);
+            set => SetValue(SubjectProperty, value);
+        }
+
+        public static readonly DependencyProperty StatusProperty = DependencyProperty.Register(
+            "Status", typeof(object), typeof(Shield), new PropertyMetadata(default(object)));
+
+        public object Status
+        {
+            get => GetValue(StatusProperty);
+            set => SetValue(StatusProperty, value);
+        }
+
+        public static readonly DependencyProperty ColorProperty = DependencyProperty.Register(
+            "Color", typeof(Brush), typeof(Shield), new PropertyMetadata(default(Brush)));
+
+        public Brush Color
+        {
+            get => (Brush) GetValue(ColorProperty);
+            set => SetValue(ColorProperty, value);
+        }
+    }
+}