Question

我创建了标题，用户名和密码的三个文本字段。我想要这样，如果标题尚未在coredata中存在，则将其添加，但是如果标题已经存在，则显示和警告消息（有效），但由于某种原因仍会添加到coredata中。 / p>

这是我的代码：

  @IBAction func savePasswordButton(_ sender: Any) {

        if let context = (UIApplication.shared.delegate as? AppDelegate)?.persistentContainer.viewContext {

            let holder = PasswordCoreData(entity: PasswordCoreData.entity(), insertInto: context)

            if let title = createHolderItem.text {
                holder.item = title
                holder.username = createHolderUsername.text!
                holder.password = createHolderPassword.text!
            }

            if homeVC.mainframe.contains(where: { $0.username == holder.username }) {
                let title = "Duplicate"
                let message = "(holder.item) already exists"
                let alert = UIAlertController(title: title, message: message, preferredStyle: UIAlertController.Style.alert)

                alert.addAction(UIAlertAction(title: "OK", style: UIAlertAction.Style.default, handler: { (action) in alert.dismiss(animated: true, completion: nil)

                }))
                self.present(alert, animated: true, completion: nil)
            }
            else {
                try? context.save()

                navigationController?.popViewController(animated: true)
            }
        }
    }

Answer 1

将int的创建移至holder。

else

如果不满足某些条件，如何防止保存输入

1 个答案: