ios - 如何在 Swift 中自动移动到下一个 UITextField

Question

我有 2 个带有 NumberPad 键盘类型的文本字段

@IBOutlet weak var ourTextField: UITextField!
@IBOutlet weak var forThemTextField: UITextField!

我想在 ourTextField 中输入两个数字后自动移动到另一个文本字段(从 ourTextField 到 forThemTextField)，然后在转到另一个文本字段(forThemTextField)并输入 2 个数字后，我希望键盘自动隐藏

我添加了一个条件，通过这段代码在我的文本字段中只接受两个数字:

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
    let lengthsDictionary = [ourTextField : 2, forThemTextField: 2]
    guard let length = lengthsDictionary[textField] else {
        return true
    }
    let currentCharacterCount = textField.text?.count ?? 0
    if (range.length + range.location > currentCharacterCount){
        return false
    }
    let newLength = currentCharacterCount + string.count - range.length

    return newLength <= length
}

Answer 1

使用 UITextFieldDelegate 方法的 shouldChangeCharactersIn 并监听键盘字符串
使用文本字段的标签，如标签 1 和标签 2

作为

class TestingViewController: UIViewController{
    @IBOutlet weak var firstTextField: UITextField!
    @IBOutlet weak var secondTextField: UITextField!

    override func viewDidLoad() {
        super.viewDidLoad()
        firstTextField.delegate = self
        secondTextField.delegate = self
        firstTextField.tag = 1
        secondTextField.tag = 2
        firstTextField.keyboardType = .numberPad
        secondTextField.keyboardType = .numberPad
    }
}

extension TestingViewController: UITextFieldDelegate {
    func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
        return textField.shouldChangeCustomOtp(textField: textField, string: string)

    }
}

extension UITextField {
    func shouldChangeCustomOtp(textField:UITextField, string: String) ->Bool {

        //Check if textField has two chacraters
        if ((textField.text?.count)! == 1  && string.count > 0) {
            let nextTag = textField.tag + 1;
            // get next responder
            var nextResponder = textField.superview?.viewWithTag(nextTag);
            if (nextResponder == nil) {
                nextResponder = textField.superview?.viewWithTag(1);
            }

            textField.text = textField.text! + string;
            //write here your last textfield tag
            if textField.tag == 2 {
                //Dissmiss keyboard on last entry
                textField.resignFirstResponder()
            }
            else {
                ///Appear keyboard
                nextResponder?.becomeFirstResponder();
            }
            return false;
        } else if ((textField.text?.count)! == 1  && string.count == 0) {// on deleteing value from Textfield

            let previousTag = textField.tag - 1;
            // get prev responder
            var previousResponder = textField.superview?.viewWithTag(previousTag);
            if (previousResponder == nil) {
                previousResponder = textField.superview?.viewWithTag(1);
            }
            textField.text = "";
            previousResponder?.becomeFirstResponder();
            return false
        }
        return true

    }

}

输出: