要编辑CoreData并更新视图,我们可以使用以下步骤和代码示例来解决问题:
创建CoreData实体模型: 首先,我们需要创建一个CoreData实体模型,其中包含我们想要存储的数据属性。可以使用Xcode的数据模型编辑器来创建实体和属性。
设置CoreData Stack: 接下来,我们需要设置CoreData Stack,即创建NSPersistentContainer实例并将其与我们的数据模型关联起来。在AppDelegate文件中,我们可以使用以下代码来设置CoreData Stack:
lazy var persistentContainer: NSPersistentContainer = {
let container = NSPersistentContainer(name: "YourDataModelName")
container.loadPersistentStores(completionHandler: { (storeDescription, error) in
if let error = error as NSError? {
fatalError("Unresolved error \(error), \(error.userInfo)")
}
})
return container
}()
let context = persistentContainer.viewContext
let entity = NSEntityDescription.entity(forEntityName: "YourEntityName", in: context)!
let newItem = NSManagedObject(entity: entity, insertInto: context)
newItem.setValue("New Item", forKey: "itemName")
do {
try context.save()
} catch {
print("Failed to save context: \(error)")
}
var fetchedResultsController: NSFetchedResultsController?
func setupFetchedResultsController() {
let fetchRequest = NSFetchRequest(entityName: "YourEntityName")
fetchRequest.sortDescriptors = [NSSortDescriptor(key: "itemName", ascending: true)]
fetchedResultsController = NSFetchedResultsController(fetchRequest: fetchRequest,
managedObjectContext: context,
sectionNameKeyPath: nil,
cacheName: nil)
fetchedResultsController?.delegate = self
do {
try fetchedResultsController?.performFetch()
} catch {
print("Failed to fetch items: \(error)")
}
}
extension YourViewController: NSFetchedResultsControllerDelegate {
func controllerDidChangeContent(_ controller: NSFetchedResultsController) {
// Update UI here
}
}
以上就是编辑CoreData和更新视图的解决方法,它涵盖了创建CoreData模型、设置CoreData Stack、编辑数据和更新视图的代码示例。根据自己的需求,可以根据这些示例进行修改和扩展。
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