Swift 核心数据更改 bool 存储答案

【问题标题】：Swift core data change bool storedSwift 核心数据更改 bool 存储
【发布时间】：2020-06-19 16:02:26
【问题描述】：

我正在为列表制作和扩展一个应用程序，并在执行过程中添加额外的数据。我添加了一个布尔值来将项目标记为已完成。

我想更改存储在核心数据中的布尔值。我可以添加和删除订单，但现在我正在寻找更改属性。请问我可以帮助我改变这些的最佳方式吗？

我已完成功能更改，但不知道如何让它在我的核心数据管理器中工作。

class CoreDataManager {

static let shared = CoreDataManager(moc: NSManagedObjectContext.current)

var moc: NSManagedObjectContext

private init(moc: NSManagedObjectContext) {
    self.moc = moc
}

private func fetchOrder(name: String) -> Order? {

    var orders = [Order]()

    let request: NSFetchRequest<Order> = Order.fetchRequest()
    request.predicate = NSPredicate(format: "name == %@", name)

    do {
        orders = try self.moc.fetch(request)
    } catch let error as NSError {
        print(error)
    }

    return orders.first

}

func changeCompleated(name:String, completed: Bool) {
      do {
        if let order = fetchOrder(name: name) {
            self.moc.perform {

            }
                 try self.moc.save()
             }
         } catch let error as NSError {
             print(error)
         }
}

func deleteOrder(name: String) {

    do {
        if let order = fetchOrder(name: name) {
            self.moc.delete(order)
            try self.moc.save()
        }
    } catch let error as NSError {
        print(error)
    }

}

func getAllOrders() -> [Order] {

    var orders = [Order]()

    let orderRequest: NSFetchRequest<Order> = Order.fetchRequest()

    do {
        orders = try self.moc.fetch(orderRequest)
    } catch let error as NSError {
        print(error)
    }

    return orders

}

func saveOrder(id: UUID, name: String, type: String, qty: Double, urgent: Bool, complete: Bool) {

    let order = Order(context: self.moc)
    order.id = id
    order.name = name
    order.type = type
    order.qty = qty
    order.urgent = urgent
    order.complete = complete

    do {
        try self.moc.save()
    } catch let error as NSError {
        print(error)
    }   
}

}

【问题讨论】：

标签： swift core-data swiftui

【解决方案1】：

差不多，只要加一行改变值，perform块就不需要了

func changeCompleated(name: String, completed: Bool) {

    guard let order = fetchOrder(name: name) else { return }
    do {
       order.complete = completed
       try self.moc.save()
    } catch {
       print(error)
    }
}

你也可以缩短fetchOrder

private func fetchOrder(name: String) -> Order? {

    let request: NSFetchRequest<Order> = Order.fetchRequest()
    request.predicate = NSPredicate(format: "name == %@", name)

    do {
        return try self.moc.fetch(request).first
    } catch {
        print(error)
    }
 }

【讨论】：