小编Ste*_* L.的帖子

出于某种原因,我无法弄清楚如何将图像保存到核心数据并再次获取它们.我觉得这是我的类型,但看看:

我从api调用我的服务器获取数据.它返回一个base64字符串.这是我获取数据的地方:

updateAccessTokenOnly(newAccessToken: aToken!)
saveImageToDB(brandName: imageBrandName, image: data! )

在这里,我将它保存到我的DB:

func saveImageToDB(brandName: String, image: Data) {
    dropImages(){tableDropped in
        let managedContext = getContext()
        let entity = NSEntityDescription.entity(forEntityName: "CoffeeShopImage", in: managedContext)!
        let CSI = NSManagedObject(entity: entity, insertInto: managedContext)

        CSI.setValue(image, forKey: "image")
        CSI.setValue(brandName, forKey: "brandName")

        do {
            try managedContext.save()
            print("saved!")
        } catch let error as NSError {
            print("Could not save. \(error), \(error.userInfo)")
        }
    }
}

然后去取它:

    func getImageFromDB(callback: @escaping (_ image: UIImage)-> ()) {

    let fetchRequest: NSFetchRequest<NSManagedObject> = NSFetchRequest(entityName: "CoffeeShopImage")

    do {
        let …

因此,当我尝试将部署目标设置为iOS 9时(实际上低于10.0),我会收到标题中所述的错误.

这里存在的问题是:

// MARK: - Core Data stack

lazy var persistentContainer: NSPersistentContainer = {
    /*
     The persistent container for the application. This implementation
     creates and returns a container, having loaded the store for the
     application to it. This property is optional since there are legitimate
     error conditions that could cause the creation of the store to fail.
    */
    let container = NSPersistentContainer(name: "Keebin_development_1")
    container.loadPersistentStores(completionHandler: { (storeDescription, error) in
        if let error = error as NSError? {
            // Replace this …