Prism - Under the MVVM pattern, StackPanel added and deleted View (UserControl)

First, the reality effect

In the study Prim, see the official example of 03-CustomRegions just a simple demonstration, here MVVM way to be a relatively complete example, to achieve the effect shown:

Click Add, to the right to add a StackPanel View (ie UserControl), click Remove, delete one by one.

Second, the project structure

Project Source: Source download

StackPanelRegionAdapter.cs