How to add a Window to Frame Or Grid?

Question

Hi

To all users.

I have two windows.

In the first window, a "grid" and "frame" and "button" there.

The second window can be anything. 

Now I want when I click on a button within the first window at run-time, the second window within the "frame" or "grade" is displayed.

I was able to do so with the "Page" to do.

But can not "Window" to do this.

 

=============================

The "WinForm" we simply did it:

For Example:

panel1.Controls.Add(new Form1());

 

But "WPF" If you do not know what is.

Thanks