判斷ＡＰＰ是否第一次開起（Swfit）

當我們要判斷用戶是否第一次開起ＡＰＰ時必須在APPDelegate的didFinishLauchingWithOptions下存取兩組BOOL進去userDefaults
再利用存進去的userDefaults做判斷
第一次啟動為true
之後將第二個BOOL變為false

  func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

        

判斷當"abcd"如果是false或是空時做什麼動作,如果不是空就跳到else也就是非第一次開起

        if(!UserDefaults.standard.bool(forKey: "abcd")){

            UserDefaults.standard.set(true, forKey: "abcd")

            UserDefaults.standard.set(true, forKey: "first")

            print("first")

        }else{

            UserDefaults.standard.set(false, forKey: "first")

            print("unfirst")

        }

        

        

        

        return true

    }

簡單的做個lable來測試是否有判斷成功（也可使用alert）

 override func viewDidLoad() {

        super.viewDidLoad()

    

        if (UserDefaults.standard.bool(forKey: "first")){

           let lable = UILabel(frame: CGRect(x: 50, y: 200, width: 200, height: 36))

            lable.text = "第一次開起"

            lable.backgroundColor = UIColor.red

            lable.textColor = UIColor.yellow

            self.view.addSubview(lable)

        }else{

            let lable = UILabel(frame: CGRect(x: 50, y: 200, width: 200, height: 36))

            lable.text = "非第一次開起"

            lable.backgroundColor = UIColor.blue

            lable.textColor = UIColor.white

            self.view.addSubview(lable)

        }

    }

下圖為測試結果

監聽動作 (Swift)

下列程式碼為簡單的監聽應用，監聽可運用在很多地方。

監聽函數NSNotificationCenter.defaultCenter().addObserver(<#T##observer: AnyObject##AnyObject#>,<-self
 selector: <#T##Selector#>, <-自定義的func名稱，記得前面要帶上#selector(controller名稱.func名稱)
name: <#T##String?#>, <-自定義一個名稱，當呼叫監聽時需要用到
object: <#T##AnyObject?#>)<-如沒有object動做時則為nil，目前我用到幾乎都是使用nil

呼叫監聽動作函數NSNotificationCenter.defaultCenter().postNotificationName(
<#T##aName: String##String#>,<-在監聽時自定義的名稱
object: <#T##AnyObject?#>)<-同監聽時的object

監聽動作函數有很多種可以選擇，使用時可多研究哪一種是你當下需求最好的。

Swift 3

import UIKit

class ViewController: UIViewController {

    @IBOutlet weak var label: UILabel!

    

    override func viewDidLoad() {

        super.viewDidLoad()

        // Do any additional setup after loading the view, typically from a nib.

        

//        當值行以下時進行監聽動作

        NotificationCenter.default.addObserver(self, selector: #selector(ViewController.leableText), name: NSNotification.Name(rawValue: "test"), object: nil)

        

    }

    override func didReceiveMemoryWarning() {

        super.didReceiveMemoryWarning()

        // Dispose of any resources that can be recreated.

    }

    @IBAction func button(sender: UIButton) {

//        間聽到時值行該動作

        NotificationCenter.default.post(name: NSNotification.Name(rawValue: "test"), object: nil);

    

    }

    func leableText(){

        label.text = "監聽";

        label.textColor = UIColor.blue

        label.backgroundColor = UIColor.red

    }

}

Swift2.3

import UIKit

class ViewController: UIViewController {

    @IBOutlet weak var label: UILabel!

    

    override func viewDidLoad() {

        super.viewDidLoad()

        

        

//        當值行以下時進行監聽動作

        NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(ViewController.leableText), name: "test", object: nil)

    }

    override func didReceiveMemoryWarning() {

        super.didReceiveMemoryWarning()

        // Dispose of any resources that can be recreated.

    }

    @IBAction func button(sender: UIButton) {

//        間聽到時值行該動作

        NSNotificationCenter.defaultCenter().postNotificationName("test", object: nil);

    }

    func leableText(){

        label.text = "監聽";

        label.textColor = UIColor.blueColor()

        label.backgroundColor = UIColor.redColor()

    }

}

執行動作前如下圖

因viewDidLoad設定了監聽，

所以APP一執行時就進行了監聽func leableText()裡面要執行的程序

當點擊button則執行監聽動作如下圖

UserDefaults 資料存取（Swift）

存取欄位資料
Swift 3

2016/11/16補充
今天補充swift3在其他class時使用UserDefaults取出原本以存入的資料
首先可先建立一個新的class，在這我直接建立兩個新的label及一個button
button內所做的就是將原本前一個class已經輸入的資料呼叫出來並輸入新建立的label
當我們存入資料時是使用UserDefaults.standard.setValue(Any?, forKey: String)
呼叫資料時使用UserDefaults.standard.string(forKey: String)

@IBOutlet weak var passwordLabel: UILabel!

@IBOutlet weak var IdLabel: UILabel!

 @IBAction func loadingBtn(_ sender: UIButton) {

        IdLabel.text = UserDefaults.standard.string(forKey: "id")

        passwordLabel.text = UserDefaults.standard.string(forKey: "pas")

    }

-------------------------------------------------虛線以上為補充----------------------------------------------------

import UIKit

class ViewController: UIViewController,UITextFieldDelegate {

    

    

    @IBOutlet weak var ID: UITextField!

    @IBOutlet weak var PassWord: UITextField!

    

    var UserDef:UserDefaults!

    var Id:String!

    var pas:String!

    var info:String!

    var info2:String!

    

    

    override func viewDidLoad() {

        super.viewDidLoad()

        // Do any additional setup after loading the view, typically from a nib.

        ID.delegate = self

        PassWord.delegate = self

        //        ID.enablesReturnKeyAutomatically = true

        //        PassWord.enablesReturnKeyAutomatically = true

        UserDef = UserDefaults.standard

        

        

    }

    

    override func didReceiveMemoryWarning() {

        super.didReceiveMemoryWarning()

        // Dispose of any resources that can be recreated.

    }

    

    @IBAction func OKButton(sender: UIButton) {

        

        Id = ID.text;

        pas = PassWord.text;

        UserDef.setValue(Id, forKey: "id")

        UserDef.setValue(pas, forKey: "pas")

        

        

        info = UserDef.string(forKey: "id");

        info2 = UserDef.string(forKey: "pas");

        

        //        print(info)

        //        print(info2)

        

        

    }

    

    @IBAction func PrintButton(sender: UIButton) {

        

        let leable:UILabel = UILabel.init(frame: CGRect(x: 50, y: 200, width: 100, height: 36));

        leable.backgroundColor = UIColor.red

        

        let leable2:UILabel = UILabel.init(frame: CGRect(x: 50, y: 237, width: 100, height: 36));

        leable2.backgroundColor = UIColor.red

        

        

        

        if let userID = UserDef.string(forKey: "id"){

            

            leable.text = userID

            self.view.addSubview(leable);

            

        }else{

            leable.backgroundColor = UIColor.blue

            

        }

        if let aaa = UserDef.string(forKey: "pas"){

            leable2.text = aaa

            self.view.addSubview(leable2)

        }else{

            leable2.backgroundColor = UIColor.blue

        }

        

    }

}

Swift 2.3

import UIKit

class ViewController: UIViewController,UITextFieldDelegate {

    

    

    @IBOutlet weak var ID: UITextField!

    @IBOutlet weak var PassWord: UITextField!

    

    var UserDef:NSUserDefaults!

    var Id:String!

    var pas:String!

    var info:String!

    var info2:String!

    

    

    override func viewDidLoad() {

        super.viewDidLoad()

        // Do any additional setup after loading the view, typically from a nib.

        ID.delegate = self

        PassWord.delegate = self

//        ID.enablesReturnKeyAutomatically = true

//        PassWord.enablesReturnKeyAutomatically = true

        UserDef = NSUserDefaults.standardUserDefaults()

        

        

    }

    

    override func didReceiveMemoryWarning() {

        super.didReceiveMemoryWarning()

        // Dispose of any resources that can be recreated.

    }

    

    @IBAction func OKButton(sender: UIButton) {

        

        Id = ID.text;

        pas = PassWord.text;

        UserDef.setValue(Id, forKey: "id")

        UserDef.setValue(pas, forKey: "pas")

        

        

         info = UserDef.stringForKey("id");

         info2 = UserDef.stringForKey("pas");

        

        print(info)

       print(info2)

        

        

    }

    

    @IBAction func PrintButton(sender: UIButton) {

        

        let leable:UILabel = UILabel.init(frame: CGRect(x: 50, y: 200, width: 100, height: 36));

        leable.backgroundColor = UIColor.redColor()

        

        let leable2:UILabel = UILabel.init(frame: CGRect(x: 50, y: 237, width: 100, height: 36));

        leable2.backgroundColor = UIColor.redColor()

        

        

        if let userID = UserDef.stringForKey("id"){

           

            leable.text = userID

            

        self.view.addSubview(leable);

        

        }else{

        leable.backgroundColor = UIColor.blueColor()

            

        }

        if let aaa = UserDef.stringForKey("pas"){

            leable2.text = aaa

            self.view.addSubview(leable2)

        }else{

            leable2.backgroundColor = UIColor.blueColor()

        }

        

    }

}

第一次輸入後畫面如下

 將ＡＰＰ玩全關必後開起在值接按書出後顯是如下

如按下輸出後沒顯示出來label被景為藍色時表示存取沒有成功或資料是空

BASE64加密(Swift)

使用原生簡易加密BASE64

Swift 3

import UIKit

class ViewController: UIViewController {

    

    var base64String:String!

    var Lable1:UILabel!

    var Lable2:UILabel!

    

    @IBOutlet weak var string: UITextField!

    

    override func viewDidLoad() {

        

        super.viewDidLoad()

        // Do any additional setup after loading the view, typically from a nib.

        string.backgroundColor = UIColor.brown

        string.alpha = 0.7;

        

        Lable1 = UILabel.init(frame: CGRect(x: 10, y: 150, width: 320, height: 36));

        Lable1.backgroundColor = UIColor.gray

        Lable1.alpha = 0.5

        

        Lable2 = UILabel.init(frame: CGRect(x: 10, y: 190, width: 320, height: 36));

        Lable2.backgroundColor = UIColor.red

        Lable2.alpha = 0.5;

        

    }

    

    override func didReceiveMemoryWarning() {

        super.didReceiveMemoryWarning()

        // Dispose of any resources that can be recreated.

    }

    

    @IBAction func encryptionBtn(_ sender: UIButton) {

        let StringText = string.text;

        let base64Data = StringText!.data(using: String.Encoding.utf8)

        

        base64String = base64Data?.base64EncodedString(options: .lineLength64Characters)

        

        print(base64String)

        

        Lable1.text = "這是加密結果：\(base64String)";

       

        self.view.addSubview(Lable1);

    }

    

    @IBAction func UnencryptionBtn(_ sender: UIButton) {

        if(base64String != nil){

            let decodedData = Data(base64Encoded: base64String!, options: .ignoreUnknownCharacters)

            

            let decodedString = NSString(data: decodedData!, encoding: String.Encoding.utf8.rawValue) as! String

            

            print(decodedString)

            

            Lable2.text = "這是解密結果：\(decodedString)";

            self.view.addSubview(Lable2);

        }

    }

    @IBAction func cleanBtn(_ sender: UIButton) {

        string.text = nil

        

        Lable1.text = ""

        Lable1.removeFromSuperview()

        

        Lable2.text = ""

        Lable2.removeFromSuperview()

    }

}

Swfit 2.3

override func viewDidLoad() {

        super.viewDidLoad()

let string = "test"

  //加密使用base64

           

let base64Data = string.dataUsingEncoding(NSUTF8StringEncoding)

            

let base64String = base64Data?.base64EncodedStringWithOptions(.Encoding64CharacterLineLength)

          

  print(base64String)  //輸出後會變成(dGVzdA==)

       

     //解密base64

      

      let decodedData = NSData(base64EncodedString: base64String!, options: .IgnoreUnknownCharacters)

           

let decodedString = NSString(data: decodedData!, encoding: NSUTF8StringEncoding)

          

  print(decodedString)//輸出後會恢復(test)

}