ios - 文本字段 shouldChangeCharactersInRange 未调用

Question

问题:

文本字段不接受字符。

shouldChangeCharactersInRange 未针对所有 3 个文本字段调用。

我有 3 个委托(delegate)类的实现，就像在 main 中一样。所有方法的实现与 main 中实现的委托(delegate)方法完全相同。除 shouldChangeCharactersInRange 之外的所有其他方法均在运行时调用。编辑框根本不接受任何字符。

import UIKit

class ViewController: UIViewController , UITextFieldDelegate{

    @IBOutlet weak var textField1: UITextField!
    @IBOutlet weak var textField2: UITextField!
    @IBOutlet weak var textField3: UITextField!

    var t1Delegate : text1Delegate!
    var t2Delegate : text2Delegate!
    var t3Delegate : text3Delegate!

    override func viewDidLoad() {   
             t2Delegate = text2Delegate()
        textField2.delegate = t2Delegate
     }
    override func viewDidAppear(animated: Bool) {
        textField1.delegate = self
        textField1.becomeFirstResponder()
        t3Delegate = text3Delegate()
        textField3.delegate = t3Delegate
        super.viewDidLoad()   
    }
    func textField (textField :  UITextField, shouldChangeCharactersInRange range:  NSRange, replacementString string:  String  )  ->  Bool {
        print("*. Should change text.")
        return true;   
    }
    // UITextField Delegates
    func textFieldDidBeginEditing(textField: UITextField) {
        print("*. TextField did begin editing method called")
    }
    func textFieldDidEndEditing(textField: UITextField) {
        print("*. TextField did end editing method called")
    }
    func textFieldShouldBeginEditing(textField: UITextField) -> Bool {
        print("*. TextField should begin editing method called")
        return true;
    }
    func textFieldShouldClear(textField: UITextField) -> Bool {
        print("*. TextField should clear method called")
        return true;
    }
    func textFieldShouldEndEditing(textField: UITextField) -> Bool {
        print("*. TextField should end editing method called")
        return true;
    }

    func textFieldShouldReturn(textField: UITextField) -> Bool {
        print("*TextField should return method called")
        textField.resignFirstResponder();
        return true;
    }
}

Answer 1

在 Swift 3.0 中更改 Textfield 编辑方法。请配合下面附上的方法使用

class PromoCodeViewController: UIViewController , UITextFieldDelegate{
}

override func viewDidLoad() {
    super.viewDidLoad()

    tf_GiftVoucher.delegate = self

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

func textField(_ textField: UITextField, shouldChangeCharactersIn range:NSRange, replacementString string: String) -> Bool {
    if tf_GiftVoucher == textField {
        let text = textField.text
        if (text?.characters.count)! > 15 || string == " " {
            return false
        }
    }
    return true
}