比较UIWindow和UIView

Question

What are the differences between a UIWindow and a UIView in Objective-C?

How does the view hierarchy work? I know that you can add a UIView to a UIWindow , with something like:

[self.window addSubview:secondView];

Are you able to add a Subview to another UIView ?

Answer 1

The difference between UIWindow and UIView.

In iOS, you use windows and views to present your application's content on the screen.Windows do not have any visible content themselves but provide a basic container for your application's views. Views define a portion of a window that you want to fill with some content. For example, you might have views that display images, text, shapes, or some combination thereof. You can also use views to organize and manage other views.