환경

Swift3

Xcode8

Mac Os Sierra

copipe로 움직여야합니다.

Outlet은 스토리 보드에서

class AddTextViewController: UIViewController, UITextViewDelegate, UITextFieldDelegate {


    @IBOutlet weak var TitleText: UITextField!
    @IBOutlet weak var DetailText: UITextView!


    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)

        TitleText.text = "タイトル"
        TitleText.textColor = UIColor.lightGray
        TitleText.delegate = self

        DetailText.text = "本文"
        DetailText.textColor = UIColor.lightGray
        DetailText.delegate = self
    }

    func textViewDidBeginEditing(_ textView: UITextView) {

        print("反応")
        if DetailText.textColor == UIColor.lightGray {
            DetailText.text = nil
            DetailText.textColor = UIColor.black
        }
    }


    func textViewDidEndEditing(_ textView: UITextView) {
        if DetailText.text.isEmpty {
            DetailText.text = "本文"
            DetailText.textColor = UIColor.lightGray
        }
    }

    func textFieldDidBeginEditing(_ textField: UITextField) {
        if TitleText.textColor == UIColor.lightGray {
            TitleText.text = nil
            TitleText.textColor = UIColor.black
        }
    }

    func textFieldDidEndEditing(_ textField: UITextField) {
        if (TitleText.text?.isEmpty)! {
            TitleText.text = "タイトル"
            TitleText.textColor = UIColor.lightGray
        }
    }
}

실행

Step1

UITextViewDelegate 대리자

class MyViewController: UIViewController, UITextViewDelegate {

step2

viewWillAppear 에 아래와 같이 쓴다 bodyTextView 는 자신의 IBOutlet 입니다

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)


        bodyTextView.text = "Placeholder"
        bodyTextView.textColor = UIColor.lightGray


    }

step3

textViewDidBeginEditing 및 textViewDidEndEditing 구현

    func textViewDidBeginEditing(_ textView: UITextView) {
        if bodyTextView.textColor == UIColor.lightGray {
            bodyTextView.text = nil
            bodyTextView.textColor = UIColor.black
        }
    }


    func textViewDidEndEditing(_ textView: UITextView) {
        if bodyTextView.text.isEmpty {
            bodyTextView.text = "Placeholder"
            bodyTextView.textColor = UIColor.lightGray
        }
    }

주의점

덧붙여서 이것이라면 스토리 보드에 처음부터 붙어있는 textField의 Placeholder와는 움직임이 다르기 때문에 textField와는 병용이 불가능합니다. 그래서, textField 와 병용하는 경우는, textField 도 이번의 TextView 와 같이 구현하지 않으면 안됩니다.

step4

UITextField 대리자

class MyViewController: UIViewController, UITextFieldDelegate, UITextViewDelegate {

step5

viewWillAppear 에 아래와 같이 쓴다 titleTextField 는 자신의 IBOutlet 입니다

override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)


        bodyTextView.text = "Placeholder"
        bodyTextView.textColor = UIColor.lightGray

        titleTextField.text = "Placeholder"
        titleTextField.textColor = UIColor.lightGray


    }

step6

textFieldDidBeginEditing 및 textViewDidEndEditing 구현

      /*

     テキストフィールドもプレイスフォルダー実装

     */

    func textFieldDidBeginEditing(_ textField: UITextField) {
        if titleTextField.textColor == UIColor.lightGray {
            titleTextField.text = nil
            titleTextField.textColor = UIColor.black
        }
    }


    func textFieldDidEndEditing(_ textField: UITextField) {
        if (titleTextField.text?.isEmpty)! {
            titleTextField.text = "Placeholder"
            titleTextField.textColor = UIColor.lightGray
        }
    }

참고

Swift3 – UITextView에서 Placeholder를 Label없이 구현하는 방법