I am new to WPF. I have two windows, such as window1 and window2. I have one button in window1. If I click that button, the window2 has to open. What should I do for that?>
Assuming the second window is defined as public partial class Window2 : Window, you can do it by:
public partial class Window2 : Window
Window2 win2 = new Window2(); win2.Show();