Template to use for Making Rhino Plugin that takes input through WPF window and performs some operation in Rhino?

Question

I am learning Rhino Plugins development. My Plugin should create the following

1. Upon Loading, show WPF window which asks for input(say length).
2. Create a surface in Rhino Based on this input(say a square of length l).

I created a Project using RhinoCommon template. Did all the things mentioned in this article.

I changed the contents of RunCommand and made it create a square surface of length l(a constant did not take input from WPF). it does this correctly. But, I am unable to extend this to take input from WPF Window. I created a xaml file and a .cs file, but I run into errors like "IntializeComponent() does not exist in this context". Could anyone help in setting up the WPF window that takes input from WPF and does something with that input in the Rhino. Thanks In Advance.