当UITextField发生改变时，我该如何进行检查？

Question

当UITextField发生改变时，我该如何进行检查？

367

我正在尝试检查文本字段何时更改，相当于用于textView的函数textViewDidChange，到目前为止我已经做到了这一点：

  func textFieldDidBeginEditing(textField: UITextField) {
        if self.status.text == "" && self.username.text == "" {
            self.topRightButton.enabled = false
        } else {   
            self.topRightButton.enabled = true
        }
    }

这种方法可以工作，但是topRightButton会在用户点击文本框时立即启用，我希望它只有在实际输入文本时才启用。

- user4184036

21个回答

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- Nil · Answer 1

Swift 4

在viewDidLoad()方法中：

    //ADD BUTTON TO DISMISS KEYBOARD

    // Init a keyboard toolbar 
    let toolbar = UIView(frame: CGRect(x: 0, y: view.frame.size.height+44, width: view.frame.size.width, height: 44))
    toolbar.backgroundColor = UIColor.clear

    // Add done button
    let doneButt = UIButton(frame: CGRect(x: toolbar.frame.size.width - 60, y: 0, width: 44, height: 44))
    doneButt.setTitle("Done", for: .normal)
    doneButt.setTitleColor(MAIN_COLOR, for: .normal)
    doneButt.titleLabel?.font = UIFont(name: "Titillium-Semibold", size: 13)
    doneButt.addTarget(self, action: #selector(dismissKeyboard), for: .touchUpInside)
    toolbar.addSubview(doneButt)

    USDTextField.inputAccessoryView = toolbar

请添加此函数：

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