Sample Code for Opening a user control widget

[ShaningYu]

I loaded a sample code into the \UserControls\ folder of the project.  I want to load the widget (e.g. myControl.xaml as well as myControl.xaml.cs) as a MenuItem through a menu.   The related code is below:

                    <Button x:Name="myMenuItem1"
                            Style="{StaticResource MenuItem}"
                            ToolTipService.ToolTip="Your First Menu Here!"
                            Content="SubMenu #1" >

I tried to find a piece of sample code to triggle the widget but not successful.  If you know how, I will appreciate your help.  Thanks.