import UIKitclass FiveVC: UIViewController {    //MARK:-------- 全局 常量 设置    let IsFirstLaunch = "IsFirstLaunch"    let UserName = "UserName"    let UserPwd = "UserPwd"    var nameField = UITextField()    var PwdField = UITextField()    override func viewDidLoad() {        super.viewDidLoad()        nameField = UITextField(frame:CGRect(x:100,y:200,width:200,height:40))        nameField.backgroundColor = UIColor.cyan        nameField.placeholder = "请输入姓名"        nameField.borderStyle = UITextBorderStyle.roundedRect        self.view.addSubview(nameField)                        PwdField = UITextField(frame:CGRect(x:100,y:300,width:200,height:40))        PwdField.backgroundColor = UIColor.cyan        PwdField.placeholder = "请输入密码"        PwdField.borderStyle = UITextBorderStyle.roundedRect        self.view.addSubview(PwdField)                        let keetBtn = UIButton.init()        keetBtn.frame = CGRect(x:100,y:400,width:100,height:40)        keetBtn.backgroundColor = UIColor.cyan        keetBtn.setTitle("保存", for: UIControlState.normal)        keetBtn.setTitleColor(UIColor.black, for: UIControlState.normal)        keetBtn.addTarget(self, action: #selector(pressKeepBtn), for: UIControlEvents.touchUpInside)        self.view.addSubview(keetBtn)                        let reduceBtn = UIButton.init()        reduceBtn.frame = CGRect(x:200,y:400,width:100,height:40)        reduceBtn.backgroundColor = UIColor.cyan        reduceBtn.setTitle("清空", for: UIControlState.normal)        reduceBtn.setTitleColor(UIColor.black, for: UIControlState.normal)        reduceBtn.addTarget(self, action: #selector(pressReduceBtn), for: UIControlEvents.touchUpInside)        self.view.addSubview(reduceBtn)                let userName = LCDUserDefaultsGet(key: UserName) as! String        let userPwd = LCDUserDefaultsGet(key: UserPwd) as! String                print("\(userName):\(userPwd)")                if userName.characters.count > 0 {            freshDate(isOk: true, userName: userName, userPwd: userPwd)        }                /*        //obj 为bool值的时候 调用        if LCDUserDefaultsBool(key: UserName) {            let userName = LCDUserDefaultsGet(key: UserName) as! String            let userPwd = LCDUserDefaultsGet(key: UserPwd) as! String                        print("\(userName):\(userPwd)")        }                print(LCDUserDefaultsBool(key: UserName)) */        }        //刷新数据    func  freshDate(isOk:Bool, userName:String, userPwd:String){            if isOk {            nameField.placeholder = ""            nameField.text = userName            PwdField.placeholder = ""            PwdField.text = userPwd        }else{            nameField.placeholder = "请输入姓名"            nameField.text = ""            PwdField.placeholder = "请输入密码"            PwdField.text = ""        }    }        //保存数据    func pressKeepBtn(){                if nameField.text?.characters.count == 0 {            alterShow(titles: "请输入姓名")            return        }        if PwdField.text?.characters.count == 0 {            alterShow(titles: "请输入密码")            return        }                LCDUserDefaultsSet(key: UserName,obj: nameField.text as AnyObject)        LCDUserDefaultsSet(key: UserPwd,obj: PwdField.text as AnyObject)        LCDUserDefaultsSyn()                let userName = LCDUserDefaultsGet(key: UserName) as! String        let userPwd = LCDUserDefaultsGet(key: UserPwd) as! String                freshDate(isOk: true, userName: userName, userPwd: userPwd)        alterShow(titles: "数据已保存成功")            }        //清空数据    func pressReduceBtn(){                LCDUserDefaultsSet(key: UserName,obj: "" as AnyObject)        LCDUserDefaultsSet(key: UserPwd,obj: "" as AnyObject)        LCDUserDefaultsSyn()        freshDate(isOk: false, userName: "", userPwd: "")        alterShow(titles: "数据已清空成功")    }        //MARK:------------- LCDUserDefaults    //保存    func LCDUserDefaultsSet(key:String, obj:AnyObject) -> Void {        return UserDefaults.standard.set(obj, forKey: key)    }    //获取    func LCDUserDefaultsGet(key:String) -> AnyObject {        return UserDefaults.standard.value(forKey: key)! as AnyObject    }    //删除    func LCDUserDefaultsRemo(key:String) -> Void {        UserDefaults.standard.removeObject(forKey: key)    }        //判断bool 类型的值    func LCDUserDefaultsBool(key:String) -> Bool {        return UserDefaults.standard.bool(forKey: key)    }    func LCDUserDefaultsSyn() {        UserDefaults.standard.synchronize()    }        override func didReceiveMemoryWarning() {        super.didReceiveMemoryWarning()        // Dispose of any resources that can be recreated.    }                func alterShow(titles:String){                let alertController = UIAlertController(title: "提示",                                                message: titles, preferredStyle: UIAlertControllerStyle.alert)        let cancelAction = UIAlertAction(title: "取消", style: UIAlertActionStyle.cancel, handler: nil)        let okAction = UIAlertAction(title: "好的", style: UIAlertActionStyle.default,                                     handler: {                                        action in                                        print("点击了确定")        })        alertController.addAction(cancelAction)        alertController.addAction(okAction)        self.present(alertController, animated: true, completion: nil)    }}