iOS开发笔记-65:swift-textFieldDidCha

swift中TextFieldDelegate没有：

• (void)textFieldDidChange:(UITextField *)textField
  需要自己来监听

textField.addTarget(self, action: #selector(self.textFieldDidChange(_:)), for: UIControlEvents.editingChanged)

@objc func textFieldDidChange(_ textfield : UITextField) {
//        JJLog(textfield.text)
    }