iOS Programming (bilingual edition)-View

1. What is a view?

The view is displayed as a rectangular area on the phone, which is a subclass of UIView or UIView.

Views can be either generated from Xib or generated in code.

2. Windows

A window is a uiwindow or a subclass of it.

The top level of the view structure is the app's window.

The window must be filled with the screen of the device, so the frame of the window must be set to the bounds of the screen.

(I'll explain the difference between frame and bounds later)

The code is as follows:

Objective-c

uiwindow* w = [[UIWindow alloc] initwithframe:[[uiscreen mainscreen] bounds]];

Swift (IOS 8)

Let w = UIWindow (Frame:UIScreen.mainScreen (). Bounds)

IOS9 after the code is significantly simplified, the system will default to the screen bounds assigned to the window frame

Swift (IOS 9)

Let w = UIWindow ()

iOS Programming (bilingual edition)-View