检查 UITextfield 是否处于活动状态

Question

问题是 "Eye Button" 应该只在文本域被选中时显示。我已经用 "isFirstResponder" 试过了，但这似乎不起作用。任何想法如何处理这个？在下面的图片中，未选择文本字段。

更新

委托函数"password did change"工作正常。我唯一需要的是，如果不再选择文本字段，按钮应该隐藏。添加委托函数 "beging" 或 "endEditing" 不起作用。如果用户输入内容，取消选择文本字段并再次选择它，它只会导致另一个失败，即文本被删除。

@IBAction func passwordDidChange(_ sender: Any) {
    if self.passwordTextField.text == "" && self.passwordTextField.isFirstResponder != true{
        self.eyeOpenButton.isHidden = true
    }else {
        self.eyeOpenButton.isHidden = false
    }

Answer 1

你可以尝试这样的事情。

class ViewController: UIViewController, UITextFieldDelegate {

    @IBOutlet weak var passwordTextField: UITextField!

    override func viewDidLoad() {
        super.viewDidLoad()
        self.eyeOpenButton.isHidden = true
        passwordTextField.delegate = self
    }

    // calls when textfield becomes 1st responder
    func textFieldShouldBeginEditing(_ textField: UITextField) -> Bool {
        switch textField {
        case passwordTextField:

            if passwordTextField.text != "" {
                self.eyeOpenButton.isHidden = !self.eyeOpenButton.isHidden
            } else {
                self.eyeOpenButton.isHidden = !self.eyeOpenButton.isHidden
            }

            break
        default:
            break
        }
        return true
    }

    //Calls when the text fields resigns first responder
    func textFieldShouldEndEditing(_ textField: UITextField) -> Bool {

        if textField == passwordTextField {
            if passwordTextField.text != "" {
                self.eyeOpenButton.isHidden = !self.eyeOpenButton.isHidden
            } else {
                self.eyeOpenButton.isHidden = !self.eyeOpenButton.isHidden
            }
        }
        return true
    }

    // Check all the input user has with the keyboard.
    func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
        if let passwordTextField = passwordTextField {

            if passwordTextField.text?.count ?? 0 > 0 {
                self.eyeOpenButton.isHidden = !self.eyeOpenButton.isHidden
            }

            if passwordTextField.text?.count == 0 {
                 self.eyeOpenButton.isHidden = !self.eyeOpenButton.isHidden
            }
        }

        return true
    }

    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        for textField in self.view.subviews where textField is UITextField {
            textField.resignFirstResponder()
        }
        return true
    }
}

Answer 2

您需要在 UITextfieldDelegate 方法中处理此问题。实施这些方法并听取变化并采取相应行动。

检查 UITextfield 是否处于活动状态

Check if UITextfield is active

uibutton

uitextfield

ios

swift