init branch

src/Shared/HandyControlDemo_Shared/UserControl/Controls/CheckComboBoxDemoCtl.xaml

@@ -0,0 +1,14 @@
+<UserControl x:Class="HandyControlDemo.UserControl.CheckComboBoxDemoCtl"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:hc="https://handyorg.github.io/handycontrol"
+             Background="{DynamicResource RegionBrush}">
+    <hc:TransitioningContentControl>
+        <hc:CheckComboBox VerticalAlignment="Top" Margin="32" ShowSelectAllButton="True" Width="180">
+            <hc:CheckComboBoxItem Content="111"/>
+            <hc:CheckComboBoxItem Content="222"/>
+            <hc:CheckComboBoxItem Content="333"/>
+            <hc:CheckComboBoxItem Content="444"/>
+        </hc:CheckComboBox>
+    </hc:TransitioningContentControl>
+</UserControl>

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

@@ -0,0 +1,10 @@
+namespace HandyControlDemo.UserControl
+{
+    public partial class CheckComboBoxDemoCtl
+    {
+        public CheckComboBoxDemoCtl()
+        {
+            InitializeComponent();
+        }
+    }
+}