The Window Class
As you learned in Chapter 5, the Window class derives from ContentControl. That means it can contain a single child (usually a layout container such as the Grid control), and you can paint the background with a brush by setting the Background property. You can also use the BorderBrush and BorderThickness properties to add a border around your window, but this border is added inside the window frame (around the edge of the client area). You can remove the window frame altogether by setting the WindowStyle property to None, which allows you to create a completely customized window, as you'll see later in the "Nonrectangular Windows" section.
The client area is the surface inside the window boundaries. This is where you place ...