如何稍后在环境中更新ManagedObjectContext

let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext

let newObject = NSEntityDescription.insertNewObject(forEntityName: "EntityName", into: context)
newObject.setValue("Value", forKey: "attributeKey")

let fetchRequest: NSFetchRequest<EntityName> = EntityName.fetchRequest()
fetchRequest.predicate = NSPredicate(format: "attributeKey == %@", "Value")
do {
    let results = try context.fetch(fetchRequest)
    if let objectToUpdate = results.first {
        objectToUpdate.attributeKey = "NewValue"
    }
} catch {
    print("Error fetching objects: \(error)")
}

let fetchRequest: NSFetchRequest<EntityName> = EntityName.fetchRequest()
fetchRequest.predicate = NSPredicate(format: "attributeKey == %@", "Value")
do {
    let results = try context.fetch(fetchRequest)
    for objectToDelete in results {
        context.delete(objectToDelete)
    }
} catch {
    print("Error fetching objects: \(error)")
}

do {
    try context.save()
} catch {
    print("Error saving context: \(error)")
}