update to v1.3.1

HandyControlDemo/ViewModel/ViewModelLocator.cs

@@ -14,6 +14,7 @@ namespace HandyControlDemo.ViewModel
             SimpleIoc.Default.Register<MainViewModel>();
             SimpleIoc.Default.Register<GrowlDemoViewModel>();
             SimpleIoc.Default.Register<ImageBrowserDemoViewModel>();
+            SimpleIoc.Default.Register<ComboBoxDemoViewModel>();
         }
 
         public static ViewModelLocator Instance => new Lazy<ViewModelLocator>(() =>
@@ -27,6 +28,8 @@ namespace HandyControlDemo.ViewModel
 
         public ImageBrowserDemoViewModel ImageBrowserDemo => ServiceLocator.Current.GetInstance<ImageBrowserDemoViewModel>();
 
+        public ComboBoxDemoViewModel ComboBoxDemo => ServiceLocator.Current.GetInstance<ComboBoxDemoViewModel>();
+
         #endregion
     }
 }