Question

我正在尝试在UserDefaults中存储一个数组但却找不到解决方案。我有一个py34和struct设置，用于在数组中存储“name”和“description”。代码如下......

func

将数据存储在UserDefaults中的最佳方法是什么，并在重新启动后将信息添加到struct task { var name = "Untitled" var description = "No description available" } var tasks = [task]() func addTask(name: String, description: String) { tasks.append(task(name: name, description: description)) }和cell.textLabel?.text？

Answer 1

以Swift惯例命名以大写字母开头的结构。您需要创建一个类，使其符合NSCoding并使用KeyedArchiever来保存对象数据

class Task: NSObject, NSCoding {
    let name: String
    let desc: String
    required init(name: String, desc: String) {
        self.name = name
        self.desc = desc
    }
    func encode(with coder: NSCoder) {
        coder.encode(name, forKey: "name")
        coder.encode(desc, forKey: "desc")
    }
    required init(coder decoder: NSCoder) {
        self.name = decoder.decodeObject(forKey: "name") as? String ?? ""
        self.desc = decoder.decodeObject(forKey: "desc") as? String ?? ""
    }
}

测试

class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate  {
    @IBOutlet weak var nameField: UITextField!
    @IBOutlet weak var descField: UITextField!
    @IBOutlet weak var tableView: UITableView!
    var tasks: [Task] = []
    override func viewDidLoad() {
        super.viewDidLoad()
        tableView.delegate = self
        tableView.dataSource = self
        if let data = UserDefaults.standard.data(forKey: "tasks") {
            tasks = NSKeyedUnarchiver.unarchiveObject(with: data) as? [Task] ?? []
            tableView.reloadData()
        }
    }
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }
    @IBAction func addTask(_ sender: UIButton) {
        guard let name = nameField.text, let desc = descField.text else { return }
        tasks.append(Task(name: name, desc: desc))
        UserDefaults.standard.set(NSKeyedArchiver.archivedData(withRootObject: tasks) , forKey: "tasks")
        tableView.reloadData()
    }
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return tasks.count
    }
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "cellID")!
        cell.textLabel?.text = tasks[indexPath.row].name + " - " + tasks[indexPath.row].desc
        return cell
    }
}

Swift 3.0：在tableView的UserDefaults中存储数组

1 个答案: