ios - 如何快速设置警报文本字段中的数字输入 20 至 20000 数字？

Question

    let alertController = UIAlertController(title: "Interval Mode", message: "Please input 20 to 20000 ms", preferredStyle: .alert)

    let confirmAction = UIAlertAction(title: "Confirm", style: .default) { (_) in

        let txtMiliSecond = alertController.textFields?[0]
    }

    let cancelAction = UIAlertAction(title: "Cancel", style: .cancel) { (_) in }

    alertController.addTextField {
            (textField) in textField.placeholder = "Enter 20 to 20000 ms";
            textField.keyboardType = .numberPad
    }

Answer 1

您需要在文本字段中的文本更改时添加目标

 alertController.addTextField { (textField : UITextField!) -> Void in
        textField.placeholder = "Enter Reason"
        textField.addTarget(self, action: #selector(self.textFieldDidChange(_:)), for: .editingChanged)
        self.saveAction.isEnabled = false
    }

然后，在文本字段更改时执行一些操作。

 func textFieldDidChange(_ textField: UITextField) {
    if(textField.text?.isEmpty == true){
        //Disable Button
        saveAction.isEnabled = false
    }else{
        //Enable button
        saveAction.isEnabled = true
    }
}

在此示例中，我根据文本字段启用/禁用保存按钮