Swift 语法糖then

then是一个swift初始化库,只有80几行的代码库,确可以让初始化变得很优雅。

1.使用then初始化AnyObject,这里以初始化控件为例

lazy var label = UILabel().then({
        $.text = "label"
        $.textColor = .blue
    })

let redView = UIView().then { (make) in
        make.backgroundColor = .red
        make.frame = CGRect(x: , y: , width: , height: )
    }

let button = UIButton().then ({
            $.setTitle("点我", for: .normal)
            $.setTitleColor(.red, for: .normal)
        })

2.then和SnapKit一起使用的方式

let button1 = UIButton().then { (make) in
            make.setTitle("登录", for: .normal)
            make.setTitleColor(.black, for: .normal)
            view.addSubview(make)

            make.snp.makeConstraints({ (make) in
                make.top.left.right.equalTo()
                make.height.equalTo()
            })
        }

let button2 = UIButton().then({
        $.setTitle("登录", for: .normal)
        $.setTitleColor(.black, for: .normal)
        view.addSubview($)

        $.snp.makeConstraints({
            $.top.equalTo(button1.snp.bottom)
            $.left.right.equalTo()
            $.height.equalTo()
        })
      })

3.其他用法

let newFrame = oldFrame.with {
          $.size.width =
          $.size.height =
    }
    newFrame.width //
    newFrame.height //

UserDefaults.standard.do {
        $.set("devxoul", forKey: "username")
        $.set("devxoul@gmail.com", forKey: "email")
        $.synchronize()
    }