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PlaceHolder s'anime lorsque vous commencez à taper dans TextField dans iOS

Comment définir ce type d'animation dans UITextField? De nos jours, de nombreuses applications l'utilisent.

 enter image description here

18
Meet Doshi

J'ai trouvé la solution. Vous pouvez gérer ce type d'animation à l'aide de plusieurs étiquettes et afficher-masquer ces étiquettes dans la méthode textFieldDidBeginEditing.

Si vous souhaitez que l'animation Nice soit identique à celle que vous décrivez dans votre question, essayez une fois de plus le référentiel tiers suivant pour UITextField.

Si vous recherchez l'équivalent UITextView de cette animation, veuillez visiter UIFloatLabelTextView repository.

15
Meet Doshi

Ce problème peut être résolu logiquement avec l'utilisation de plusieurs étiquettes et de champs de texte. Nous pouvons ensuite ajouter une animation si nécessaire. Je voudrais expliquer ce problème en utilisant trois images, à savoir Img1, Img2 et Img3. 

Img1 pointe vers le storyboard, où nous avons conçu notre interface. Ici, nous avons utilisé trois étiquettes, chacune suivie de TextField et UIView (ligne sous Textfield).

Img2: Il pointe vers l'écran initial lorsque l'application est lancée ou lorsque nous appuyons sur le bouton "Inscription" en bas, ce qui réinitialise l'écran. Dans cette image, les étiquettes sont masquées, les champs de texte étant vides et la couleur d'affichage est grise.

Img3: cette image reflète l'édition de Textfield. Lorsque nous commençons à modifier le champ de texte (ici le premier, à savoir le nom), l’étiquette apparaît, la taille du champ de texte diminue, les changements d’espace réservé et la couleur de la vue deviennent noirs. 

Nous devons garder une chose de plus à l'esprit, lorsque nous arrêtons de modifier un champ de texte et s'il est toujours vide, nous lui affectons les propriétés d'origine.

J'ajoute du code pour cette Question qui m'a été demandé comme tâche dans une interview.

import UIKit

class FloatingLabelViewController: UIViewController, UITextFieldDelegate, UINavigationControllerDelegate {


  //UITextFieldDelegate - protocol defines methods that you use to manage the editing and validation of text in a UITextField object. All of the methods of this protocol are optional.

  //UINavigationControllerDelegate - Use a navigation controller delegate (a custom object that implements this protocol) to modify behavior when a view controller is pushed or popped from the navigation stack of a UINavigationController object.

  @IBOutlet weak var NameLbl: UILabel!
  @IBOutlet weak var EmailLbl: UILabel!
  @IBOutlet weak var PasswordLbl: UILabel!

  @IBOutlet weak var NameTxf: UITextField!
  @IBOutlet weak var EmailTxf: UITextField!
  @IBOutlet weak var PasswordTxf: UITextField!

  @IBOutlet weak var SignUpBtn: UIButton!

  @IBOutlet weak var NameView: UIView!
  @IBOutlet weak var EmailView: UIView!
  @IBOutlet weak var PasswordView: UIView!


  override func viewDidLoad() {
    super.viewDidLoad()


    NameTxf.delegate = self
    EmailTxf.delegate = self
    PasswordTxf.delegate = self

    self.property()

    //black  is varaiable here
    //setTitleColor - Sets the color of the title to use for the specified state
    //var layer - The view’s Core Animation layer used for rendering. this propert is never nil
    //cg color - Quartz color refernce

    SignUpBtn.backgroundColor = UIColor.black
    SignUpBtn.setTitleColor(UIColor.white, for: .normal)
    SignUpBtn.layer.borderWidth = 1
    SignUpBtn.layer.borderColor = UIColor.black.cgColor

    //Tap guesture recognizer to hide keyboard
    let tap: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(FloatingLabelViewController.dismissKeyboard))
    view.addGestureRecognizer(tap)

    // UITapGestureRecognizer - UITapGestureRecognizer is a concrete subclass of UIGestureRecognizer that looks for single or multiple taps. For the gesture to be recognized, the specified number of fingers must tap the view a specified number of times.


  }

  override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()

  }

  //textFieldShouldReturn - Asks the delegate if the text field should process the pressing of the return button. The text field calls this method whenever the user taps the return button.  YES if the text field should implement its default behavior for the return button; otherwise, NO.

  // endEditing - Causes the view (or one of its embedded text fields) to resign the first responder status.

  func textFieldShouldReturn(_ textField: UITextField) -> Bool {
    self.view.endEditing(true)
    return false
  }


  func dismissKeyboard() {
    //Causes the view (or one of its embedded text fields) to resign the first responder status.
    view.endEditing(true)
  }

  //When user Starts Editing the textfield
  // textFieldDidBeginEditing - Tells the delegate that editing began in the specified text field

  func textFieldDidBeginEditing(_ textField: UITextField) {

    if textField == self.NameTxf
    {

        self.NameTxf.font = UIFont.italicSystemFont(ofSize: 15)
        self.NameLbl.isHidden = false
        self.NameLbl.text = self.NameTxf.placeholder
        self.NameTxf.placeholder = "First Last"
        NameView.backgroundColor = UIColor.black.withAlphaComponent(0.5)


    }

    else if textField == self.EmailTxf
    {
        self.EmailTxf.font = UIFont.italicSystemFont(ofSize: 15)
        self.EmailLbl.isHidden = false
        self.EmailLbl.text = self.EmailTxf.placeholder
        self.EmailTxf.placeholder = "[email protected]"
        EmailView.backgroundColor = UIColor.black.withAlphaComponent(0.5)


    }

    else if textField == self.PasswordTxf
    {
        self.PasswordTxf.font = UIFont.italicSystemFont(ofSize: 15)
        self.PasswordLbl.isHidden = false
        self.PasswordLbl.text = self.PasswordTxf.placeholder
        self.PasswordTxf.placeholder = "........."
        PasswordView.backgroundColor = UIColor.black.withAlphaComponent(0.5)


    }


  }


  //When User End editing the textfield.

  // textFieldDidEndEditing - Tells the delegate that editing stopped for the specified text field.

  func textFieldDidEndEditing(_ textField: UITextField) {


    //Checkes if textfield is empty or not after after user ends editing.
    if textField == self.NameTxf
    {
        if self.NameTxf.text == ""
        {
        self.NameTxf.font = UIFont.italicSystemFont(ofSize: 25)
        self.NameLbl.isHidden = true
        self.NameTxf.placeholder = "Name"
        NameView.backgroundColor = UIColor.lightGray.withAlphaComponent(0.5)




    }


    }


    else if textField == self.EmailTxf
    {
        if self.EmailTxf.text == ""
        {
            self.EmailTxf.font = UIFont.italicSystemFont(ofSize: 25)
            self.EmailLbl.isHidden = true
            self.EmailTxf.placeholder = "Email"
            EmailView.backgroundColor = UIColor.lightGray.withAlphaComponent(0.5)



        }


    }



    else if textField == self.PasswordTxf
    {
        if self.PasswordTxf.text == ""
        {
            self.PasswordTxf.font = UIFont.italicSystemFont(ofSize: 25)
            self.PasswordLbl.isHidden = true
            self.PasswordTxf.placeholder = "Password"
            PasswordView.backgroundColor = UIColor.lightGray.withAlphaComponent(0.5)


        }


    }


  }

  //Action on SingUp button Clicked.
  @IBAction func signupClicked(_ sender: Any) {

      self.property()
      self.dismissKeyboard() //TO dismiss the Keyboard on the click of SIGNUP button.

  }


  //Function to set the property of Textfields, Views corresponding to TextFields and Labels.
  func property(){

    NameLbl.isHidden =  true
    EmailLbl.isHidden = true
    PasswordLbl.isHidden = true

    NameTxf.text = ""
    EmailTxf.text = ""
    PasswordTxf.text = ""

    NameTxf.placeholder = "Name"
    EmailTxf.placeholder = "Email"
    PasswordTxf.placeholder = "Password"


    self.NameTxf.font = UIFont.italicSystemFont(ofSize: 25)
    self.EmailTxf.font = UIFont.italicSystemFont(ofSize: 25)
    self.PasswordTxf.font = UIFont.italicSystemFont(ofSize: 25)

    EmailTxf.keyboardType = UIKeyboardType.emailAddress
    PasswordTxf.isSecureTextEntry = true
    NameTxf.autocorrectionType = .no
    EmailTxf.autocorrectionType = .no

    NameView.backgroundColor = UIColor.lightGray.withAlphaComponent(0.5)
    EmailView.backgroundColor = UIColor.lightGray.withAlphaComponent(0.5)
    PasswordView.backgroundColor = UIColor.lightGray.withAlphaComponent(0.5)   
  }
}

 Img1 : StoryBoard

 Img2: Initial Screen  Img3: Textfield Editing

4
Rouny

Vous pouvez essayer d’utiliser JSInputField , qui prend également en charge la validation des données.

JSInputField *inputField = [[JSInputField alloc] initWithFrame:CGRectMake(10, 100, 300, 50)];
[self.view addSubview:inputField];
[inputField setPlaceholder:@"Enter Text"];
[inputField setRoundedCorners:UIRectCornerAllCorners];
[inputField addValidationRule:JSCreateRuleNotNullValue]; //This will validate field for null value. It will show error if field is empty.
[inputField addValidationRule:JSCreateRuleNumeric(2)];  //This will validate field for numeric values and restrict to enter value upto 2 decimal places.
2
Jitendra Singh

Pour Swift 4.0 et 4.2 

Vérifiez cette bibliothèque pour textField flottant

https://github.com/hasnine/iOSUtilitiesSource

Code: 

enum placeholderDirection: String {
    case placeholderUp = "up"
    case placeholderDown = "down"

}
public class IuFloatingTextFiledPlaceHolder: UITextField {
    var enableMaterialPlaceHolder : Bool = true
    var placeholderAttributes = NSDictionary()
    var lblPlaceHolder = UILabel()
    var defaultFont = UIFont()
    var difference: CGFloat = 22.0
    var directionMaterial = placeholderDirection.placeholderUp
    var isUnderLineAvailabe : Bool = true
    override init(frame: CGRect) {
        super.init(frame: frame)
        Initialize ()
    }
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        Initialize ()
    }
    func Initialize(){
        self.clipsToBounds = false
        self.addTarget(self, action: #selector(IuFloatingTextFiledPlaceHolder.textFieldDidChange), for: .editingChanged)
        self.EnableMaterialPlaceHolder(enableMaterialPlaceHolder: true)
        if isUnderLineAvailabe {
            let underLine = UIImageView()
            underLine.backgroundColor = UIColor.init(red: 197/255.0, green: 197/255.0, blue: 197/255.0, alpha: 0.8)
            //            underLine.frame = CGRectMake(0, self.frame.size.height-1, self.frame.size.width, 1)
            underLine.frame = CGRect(x: 0, y: self.frame.size.height-1, width : self.frame.size.width, height : 1)

            underLine.clipsToBounds = true
            self.addSubview(underLine)
        }
        defaultFont = self.font!

    }
    @IBInspectable var placeHolderColor: UIColor? = UIColor.lightGray {
        didSet {
            self.attributedPlaceholder = NSAttributedString(string: self.placeholder! as String ,
                                                            attributes:[NSAttributedString.Key.foregroundColor: placeHolderColor!])
        }
    }
    override public var placeholder:String?  {
        didSet {
            //  NSLog("placeholder = \(placeholder)")
        }
        willSet {
            let atts  = [NSAttributedString.Key.foregroundColor.rawValue: UIColor.lightGray, NSAttributedString.Key.font: UIFont.labelFontSize] as! [NSAttributedString.Key : Any]
            self.attributedPlaceholder = NSAttributedString(string: newValue!, attributes:atts)
            self.EnableMaterialPlaceHolder(enableMaterialPlaceHolder: self.enableMaterialPlaceHolder)
        }

    }
    override public var attributedText:NSAttributedString?  {
        didSet {
            //  NSLog("text = \(text)")
        }
        willSet {
            if (self.placeholder != nil) && (self.text != "")
            {
                let string = NSString(string : self.placeholder!)
                self.placeholderText(string)
            }

        }
    }
    @objc func textFieldDidChange(){
        if self.enableMaterialPlaceHolder {
            if (self.text == nil) || (self.text?.count)! > 0 {
                self.lblPlaceHolder.alpha = 1
                self.attributedPlaceholder = nil
                self.lblPlaceHolder.textColor = self.placeHolderColor
                self.lblPlaceHolder.frame.Origin.x = 0 ////\\
                let fontSize = self.font!.pointSize;
                self.lblPlaceHolder.font = UIFont.init(name: (self.font?.fontName)!, size: fontSize-3)
            }
            UIView.animate(withDuration: 0.5, delay: 0, usingSpringWithDamping: 0.6, initialSpringVelocity: 1, options: .curveEaseInOut, animations: {() -> Void in
                if (self.text == nil) || (self.text?.count)! <= 0 {
                    self.lblPlaceHolder.font = self.defaultFont
                    self.lblPlaceHolder.frame = CGRect(x: self.lblPlaceHolder.frame.Origin.x+10, y : 0, width :self.frame.size.width, height : self.frame.size.height)
                }
                else {
                    if self.directionMaterial == placeholderDirection.placeholderUp {
                        self.lblPlaceHolder.frame = CGRect(x : self.lblPlaceHolder.frame.Origin.x, y : -self.difference, width : self.frame.size.width, height : self.frame.size.height)
                    }else{
                        self.lblPlaceHolder.frame = CGRect(x : self.lblPlaceHolder.frame.Origin.x, y : self.difference, width : self.frame.size.width, height : self.frame.size.height)
                    }

                }
            }, completion: {(finished: Bool) -> Void in
            })
        }
    }
    func EnableMaterialPlaceHolder(enableMaterialPlaceHolder: Bool){
        self.enableMaterialPlaceHolder = enableMaterialPlaceHolder
        self.lblPlaceHolder = UILabel()
        self.lblPlaceHolder.frame = CGRect(x: 0, y : 0, width : 0, height :self.frame.size.height)
        self.lblPlaceHolder.font = UIFont.systemFont(ofSize: 10)
        self.lblPlaceHolder.alpha = 0
        self.lblPlaceHolder.clipsToBounds = true
        self.addSubview(self.lblPlaceHolder)
        self.lblPlaceHolder.attributedText = self.attributedPlaceholder
        //self.lblPlaceHolder.sizeToFit()
    }
    func placeholderText(_ placeholder: NSString){
        let atts  = [NSAttributedString.Key.foregroundColor: UIColor.lightGray, NSAttributedString.Key.font: UIFont.labelFontSize] as [NSAttributedString.Key : Any]
        self.attributedPlaceholder = NSAttributedString(string: placeholder as String , attributes:atts)
        self.EnableMaterialPlaceHolder(enableMaterialPlaceHolder: self.enableMaterialPlaceHolder)
    }
    override public func becomeFirstResponder()->(Bool){
        let returnValue = super.becomeFirstResponder()
        return returnValue
    }
    override public func resignFirstResponder()->(Bool){
        let returnValue = super.resignFirstResponder()
        return returnValue
    }

    override public func layoutSubviews() {
        super.layoutSubviews()
    }
}

2
Jamil Hasnine Tamim

utiliser ce code 

[your_textfieldname setShowsTouchWhenHighlighted:YES];
0
Abhinandan Pratap