Swift Then Swift 初始化语法糖

Then 是实现 Swift 对象初始化的一个语法糖初始化 UILabel 并设置其属性let label = UILabel().then {
$0.textAlignment = .center
$0.textColor = .black
$0.text = "Hello, World!"
}相当于：let label: UILabel = {
let label = UILabel()
label.textAlignment = .center
label.textColor = .black
label.text = "Hello, World!"
return label
}()技巧 在所有的 NSObject 子类中使用 then()  let queue = OperationQueue().then {
$0.maxConcurrentOperationCount = 1
} 在自定义类中使用，只需进行简单扩展： extension MyType: Then {}

let instance = MyType().then {
$0.really = "awesome!"
} 拷贝值类型数据时候 with()  let newFrame = oldFrame.with {
$0.size.width = 200
$0.size.height = 100
}
newFrame.width // 200
newFrame.height // 100 使用 do() 减少类型处理 UserDefaults.standard.do {
$0.set("devxoul", forKey: "username")
$0.set("[email protected]", forKey: "email")
$0.synchronize()
} 真实示例：final class MyViewController: UIViewController {

let titleLabel = UILabel().then {
$0.textColor = .black
$0.textAlignment = .center
}

let tableView = UITableView().then {
$0.backgroundColor = .clear
$0.separatorStyle = .none
$0.register(MyCell.self, forCellReuseIdentifier: "myCell")
}

override func viewDidLoad() {
super.viewDidLoad()
self.view.addSubview(self.titleLabel)
self.view.addSubview(self.tableView)
}

}安装 For iOS 8+ projects with CocoaPods: pod 'Then' For iOS 8+ projects with Carthage: github "devxoul/Then" Using Swift Package Manager: import PackageDescription

let package = Package(
name: "MyAwesomeApp",
dependencies: [
.Package(url: "https://github.com/devxoul/Then", majorVersion: 2),
]
)