Swift: 你好, AutoLayout!

main.swift

import UIKit

let argc = Process.argc
let argv = UnsafeMutablePointer<UnsafeMutablePointer<CChar>>(Process.unsafeArgv)

UIApplicationMain(argc, argv, NSStringFromClass(MainApp), NSStringFromClass(MainAppDelegate))

App.swift

import UIKit

class MainApp: UIApplication {
override func sendEvent(_ event: UIEvent) {
super.sendEvent(event)
}
}

class MainAppDelegate: UIResponder, UIApplicationDelegate {

var window: UIWindow?

func application(_ app: UIApplication, didFinishLaunchingWithOptions opt: [NSObject: AnyObject]?) -> Bool {

self.window = UIWindow(frame: UIScreen.main().bounds)

self.window!.rootViewController = UINavigationController(rootViewController:MainViewController())
self.window!.backgroundColor = UIColor.white()
self.window!.makeKeyAndVisible()

return true
}
}

ViewController.swift

import UIKit

class MainViewController: UIViewController {

var label0_: UILabel!
var label1_: UILabel!
var label2_: UILabel!

override func viewDidLoad() {
super.viewDidLoad()

self.title = "主视图"

self.label0_ = {
let label = UILabel()
label.textAlignment = .center
label.text = "Hello, AutoLayout!"
return label
}()

self.label1_ = {
let label = UILabel()
label.textColor = UIColor.red()
label.textAlignment = .center
label.text = "=== 你好, AutoLayout! ==="
return label
}()

self.label2_ = {
let label = UILabel()
label.textColor = UIColor.blue()
label.textAlignment = .center
label.text = "=== 底部 ==="
return label
}()

self.view.addSubview(self.label0_)
self.view.addSubview(self.label1_)
self.view.addSubview(self.label2_)

self.view.setupAutoLayout {
return (
layputs: [
("H:|-(20)-[label0]-20-|",[]),
("H:|-(20)-[label1]-20-|",[]),
("H:|-(20)-[label2]-20-|",[]),

("V:|[topGuide]-(0)-[label0(20)]-20-[label1(20)]-(>=0)-[label2]-[bottomGuide]|",[])
],
viewsMap: [
"topGuide": self.topLayoutGuide,
"bottomGuide": self.bottomLayoutGuide,

"label0": self.label0_,
"label1": self.label1_,
"label2": self.label2_
]
)
}
}
}

self.view.setupAutoLayout

UIView

extension UIView {
func setupAutoLayout(closure: () -> (layouts: [(String,NSLayoutFormatOptions)], viewsMap: [String:AnyObject]) ) {
let (viewsLayouts, viewsMap) = closure()

// 采用自动布局
for view in viewsMap.values {
if let v = view as? UIView {
v.translatesAutoresizingMaskIntoConstraints = false
}
}

// 添加自动布局规则
for layout in viewsLayouts {
self.addConstraints(
NSLayoutConstraint.constraints(
withVisualFormat: layout.0,
options: layout.1, metrics: nil,
views: viewsMap
)
)
}
}
}