presention和presenting直接的通信
1：通過委托的方式，presention實例化一個交互方法的委托類枚冗，presenting的delegate指向presention
2：presenting直接調(diào)用presention的方法
//找Controller中的xxxMethod方法蛇损，找到后調(diào)用淤齐，優(yōu)先在本類中招，找不到才往上游找
UIApplication.sharedApplication().sendAction("xxxMethod:", to: nil, from: self, forEvent: nil)
