tidy the codes

src/Shared/HandyControlDemo_Shared/UserControl/Controls/PoptipDemoCtl.xaml.cs

@@ -1,11 +1,10 @@
-
-namespace HandyControlDemo.UserControl
+namespace HandyControlDemo.UserControl
 {
-    public sealed partial class PoptipDemoCtl
+    public partial class PoptipDemoCtl
     {
         public PoptipDemoCtl()
         {
-            this.InitializeComponent();
+            InitializeComponent();
         }
     }
 }