Question

我创建一个数据管理器模型，这里是：

public class DataManager {

// get documents directiory
static fileprivate func getDocumentDirectory() -> URL {
    if let url = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first {
        return url
    } else {
        fatalError("Unable to access document directiory")
    }
}



// save any kind of codable objects
static func save <T: Encodable> (_ object: T, with filename: String) {
    let url = getDocumentDirectory().appendingPathComponent(filename, isDirectory: false)
    let encoder = JSONEncoder()

    do {
        let data = try encoder.encode(object)
        if FileManager.default.fileExists(atPath: url.path) {
            try FileManager.default.removeItem(at: url)
        }
        FileManager.default.createFile(atPath: url.path, contents: data, attributes: nil)
    } catch {
        fatalError(error.localizedDescription)
    }
}


// Load any kind of codable object
static func load <T: Decodable> (_ filename: String, with type: T.Type) -> T {
    let url = getDocumentDirectory().appendingPathComponent(filename, isDirectory:  false
    )
    if !FileManager.default.fileExists(atPath: url.path) {
        fatalError("File not found at path \(url.path)")
    }

    if let data = FileManager.default.contents(atPath: url.path) {
        do {
            let model = try JSONDecoder().decode(type, from: data)
            return model
        } catch {
            fatalError(error.localizedDescription)
        }
    } else {
        fatalError("Data is unavailable at path \(url.path)")
    }
}

// Load data from a file
static func loadData(_ filename: String) -> Data? {
    let url = getDocumentDirectory().appendingPathComponent(filename, isDirectory:  false
    )
    if !FileManager.default.fileExists(atPath: url.path) {
        fatalError("File not found at path \(url.path)")
    }

    if let data = FileManager.default.contents(atPath: url.path) {
        return data
    } else {
        fatalError("Data is unavailable at path \(url.path)")
    }
}


//Load all files from a directory
static func loadAll <T:Decodable> (_ type: T.Type) ->[T] {
    do {
        let files = try FileManager.default.contentsOfDirectory(atPath: getDocumentDirectory().path)
        var modelObjects = [T]()

        for filename in files {
            modelObjects.append(load(filename, with: type))
        }

        return modelObjects

    } catch {
        fatalError("Could not load any files")
    }
}



//Delete file
static func delete (_ filename: String) {
    let url = getDocumentDirectory().appendingPathComponent(filename, isDirectory: false)

    if FileManager.default.fileExists(atPath: url.path) {
        do {
            try FileManager.default.removeItem(at: url)
        } catch {
            fatalError(error.localizedDescription)
        }
    }
}

}

我添加了所有需要以某种方式回答我的代码。

在此数据管理器中，我在控制器中创建了一个数组以显示数据

 var activity = DataManager.loadAll(Activity.self)

当我从该方法保存数据时，它将完美保存，但是此数组无法立即更新以从中获取数据，因此我必须关闭应用程序，当我再次打开它时，该数组将更新为最新数据。您对此有何建议？非常感谢

在我的模型中，我还具有保存数据的功能

 func saveItem() {
    DataManager.save(self, with: identifier.uuidString)
}

然后在控制器中保存类似的数据

 let newActivity = Activity(title: "Test todo", isDone: false, DeteOfCreation: Date(), identifier: UUID())

 newActivity.saveItem()

本地存储阵列不会立即更新

0 个答案: