Error: Cannot create more than one System.Windows.Application instance in the same AppDomain - Reflection of WPF Project

I am creating a visual studio plugin which will analyze code for WPF project. I am doing reflection activity to get metadata info and also to invoke some methods or constructor. As we know wpf project has App.xaml file which is a App class. So when i try to invoke a constructor of App class then it gives me error like "Cannot create more than one System.Windows.Application instance in the same AppDomain". Code to invoke constructor is as below:

Type t = _assembly.GetType(viewclassname);
ConstructorInfo ci = t.GetConstructors()[0];
ci.Invoke(null);

So i googled for this issue and found that it is not possible to create more than one instance of System.Windows.Application in same appdomain. So i googled again for how to create a new appdomain and how to load assembly into it. But i am unable to find how to get metadata info and how to invoke a method/constructor after load the assembly into new appdomain as i did in above code. I hope i clearly described my question.

Code that i used to create appdomain and load assembly into it.

AppDomain newDomain = AppDomain.CreateDomain("NewDomain");
 newDomain.Load(assemblyPath);

So, how can i solve this issues and able to invoke constructor of System.Windows.Application class.