Swift typealias使用

typealias 类型定义总结

• 给已有类型重新定义名称，方便代码阅读
• 定义闭包，类似oc的block 定义

    //eg:1.已有类型的重新命名
    typealias  Address = CGPoint

    let point: CGPoint = CGPoint(x: 0,y: 0)
    //等价于
    let point: Address = CGPoint(x: 0,y: 0)

闭包定义

    typealias successCallback = (_ code: String, _ message: String) -> Void
    var callBack: successCallback?
    self.callBack!(code: "0",message: "ok")