错误“表达式类型 '@lvalue 字符串"是什么意思?没有更多上下文是模棱两可的"吝啬的? [英] What does error "Expression type '@lvalue String?' is ambiguous without more context" mean?

问题描述

在一个 TableView 控制器中，我有多个 UITextFields 允许用户输入一些信息并使用 Realm 保存用户输入的数据.

In a TableView Controller, I have multiple UITextFields that allow users to input some information and use Realm to save data from users' input.

我使用以下方法添加数据，但收到错误消息表达式类型‘@lvalue 字符串?’没有更多上下文是模棱两可的"

I use the following ways to add the data but I got the error saying "Expression type '@lvalue String?' is ambiguous without more context"

import UIKit
import RealmSwift

class NewIdeaCreation: UITableViewController, UITextFieldDelegate {

   let realm = try! Realm()

override func viewDidLoad() {
    super.viewDidLoad()

    // Do any additional setup after loading the view.
}    

@IBAction func createButtonPressed(_ sender: UIButton) {

    try realm.write {
        realm.add(nameTextField.text) //Error here
    }
    self.dismiss(animated: true, completion: nil)
}


@IBOutlet weak var nameTextField: UITextField!

}

我应该在这里做什么?

推荐答案

您只能将 Realm Object 保存到 Realm 数据库中.String 不是 Realm Object.

You can only save Realm Objects into a realm database. String is not an Realm Object.

您可以创建一个具有 String 的对象:

You can create an object that has a String though:

class StringObject: Object {
    @objc dynamic var string = ""
    // Your model probably have more properties. If so, add them here as well
    // If not, that's ok as well
}

现在你可以保存一个StringObject:

do {
    try realm.write {
        let stringObject = StringObject()
        stringObject.string = nameTextField.text ?? ""
        realm.add(stringObject)
    }
} catch let error {
    print(error)
}

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