键盘return键自定义

passwdInput.returnKeyType = .Next
domainInput.returnKeyType = .Done
//在willappear中获取事件
self.passwdInput.addTarget(self, action: "nextKey:", forControlEvents: .EditingDidEndOnExit)
        self.domainInput.addTarget(self, action: "nextKey:", forControlEvents: .EditingDidEndOnExit)
//触发动作
    func nextKey(sender: UITextField){
        if(sender == self.nameInput){
            self.passwdInput.becomeFirstResponder()
        }else if(sender == self.passwdInput){
            self.domainInput.becomeFirstResponder()
        }else if(sender == self.domainInput){
            login()
        }
    }