Wpf Addin's View cover other user control

Question

I cover the Backtun Shell Project step by step.

Hosting WPF Child Windows in Another Process

But when the View show in the wpf shell, it cover other usercontrol. Do not work when I set pannel.Zindex = 0.

Create view code:

    // must execute on UI thread
    public void CreateView()
    {
        View = FrameworkElementAdapters.ContractToViewAdapter(_remoteProcess.RemotePlugin.Contract);
    }

Before load addIn View

after load addIn View

wpf live tree

thanks in advance