IOS study

IOS study

//----------------------------------SHORTCUTS----------------------
AUTORESIZE LABEL ACCORDING TO TEXT
 - SELECT LABEL + press CMD + '='

STRING CONCAT
        //let passwordInput = "HI THERE"
        //let usernameInput = "HELLO THERE
        let passwordInput:String = passwordField.text ?? ""
        let usernameInput:String = userNameField.text ?? ""
        let age = 19
        
        print("userName: \(usernameInput) password: \(passwordInput) age:\(age)")
        //SAME AS
        print("userName:"+usernameInput+" password:"+passwordInput)
        //SAME AS
        print("userName: \(String(describing: usernameInput)) password: \(String(describing: passwordInput))")

CLOSING A PAGE
  - self.dismiss()


CHANGINg UIImageView image
       @IBOutlet weak var image: UIImageView!
       //...
       image.image = UIImage(named:"sample") //'image' sample is saved in Assets folder as 'sample.png'
       image.image = sample //similar as above


//----------------------------------A----------------------
//Sample playing a .wav file named "hustle-on.wav" inside the project
import AVFoundation

   var player: AVAudioPlayer!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        let path = Bundle.main.path(forResource: "hustle-on", ofType: "wav")!
        let url = URL(fileURLWithPath: path)
        do{
            player = try AVAudioPlayer(contentsOf: url)
            player.prepareToPlay()
        }catch let error as NSError{
            print(error.description)
        }
    }
    //on button click play the wav file
    @IBAction func onPowerButtonPress(_ sender: Any) {
       
        player.play()
        UIView.animate(withDuration: 2.3, animations: {
            self.rocket.frame = CGRect(x: 0, y: 150, width: 240, height: 128)
        }){(finished) in
            self.hustleLbl.isHidden = false
            self.statusLbl.isHidden = false
            
        }
    }
//----------------------------------A----------------------

//----------------------------------A----------------------
//HIDE KEYBOARD ON TOUCH OUTSIDE THE TEXTFIELD
    override func viewDidLoad() {
        super.viewDidLoad()
        addHideKeyboardOnTouchOutside()
        
    }
    func addHideKeyboardOnTouchOutside(){
        let tap: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(dismissKeyboard))
        view.addGestureRecognizer(tap)  // Allows dismissal of keyboard on tap anywhere on screen besides the keyboard itself
    }
    @objc func dismissKeyboard() {
        //Causes the view (or one of its embedded text fields) to resign the first responder status and drop into background
        view.endEditing(true)
    }
    
//----------------------------------A----------------------
//----------------------------------A----------------------
//OPENING A NEW PAGE 
1. THE STORYBOARD NEEDS TO HAVE A 'STORYBOARDID' (ex. CalendarViewController is the classname and 'CalendarViewController' is also the 
storyboard Id)
2. HERE IS THE CODE
   let pageToOpenViewController = self.storyboard?.instatiateViewController(withIdentifier: "<paste-the-storyboard-id>" as!
   <Class-name>
   self.present(pageToOpenViewController, animated:true)
   
   so it will be like this
   let pageToOpenViewController = self.storyboard?.instatiateViewController(withIdentifier: "CalendarViewController" as!
   CalendarViewController
   self.present(pageToOpenViewController, animated:true)
   
    
//----------------------------------A----------------------
//----------------------------------A----------------------
//UPDATE THE VIEW INSIDE THE MAIN THREAD

DispatchQueue.main.async
{
   //update the ui views here
}
//----------------------------------A----------------------  
    
//----------------------------------A----------------------
//CHANGE THE ROOT VIEW OF THE APP
   let pageToMakeAsRootViewController = self.storyboard?.instatiateViewController(withIdentifier: "RootViewController" as!
   RootViewController
   let appDelegate = UIApplication.shared.delegate
   appDelegate?.window??.rootViewController = homePage
   
//----------------------------------A----------------------