在Swift 5.0中

let screenSize: CGRect = UIScreen.main.bounds

斯威夫特4.0

// Screen width.
public var screenWidth: CGFloat {
    return UIScreen.main.bounds.width
}

// Screen height.
public var screenHeight: CGFloat {
    return UIScreen.main.bounds.height
}

在Swift 3.0中

let screenSize = UIScreen.main.bounds
let screenWidth = screenSize.width
let screenHeight = screenSize.height

用更古老的斯威夫特语: 你可以这样做:

let screenSize: CGRect = UIScreen.mainScreen().bounds

然后你可以像这样访问宽度和高度:

let screenWidth = screenSize.width
let screenHeight = screenSize.height

如果你想要屏幕宽度的75%，你可以这样做:

let screenWidth = screenSize.width * 0.75