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我有UISearchBar,并尝试追加一些过滤器在我的基地,但是当我试图重新加载我的NSFetchedResultsController与新谓词有时重新包含约10秒(一个谓词)和其他时间只有2秒这一谓语。在Predicates中使用的Core Data中的所有属性都被编入索引。 为什么发生这种情况以及如何解决这个问题?如何重新加载NSFetchedResultsController与新的过滤器在后台线程谓词?
fetchResultController代码
lazy var context: NSManagedObjectContext = {
let appDelegate = (UIApplication.shared.delegate as? AppDelegate)
return appDelegate!.managedObjectContext
}()
lazy var fetchedResultsController: NSFetchedResultsController<CardsBaseClass> = {
let fetchRequest = NSFetchRequest<CardsBaseClass>(entityName: "CardsBase")
let sortDescriptor = NSSortDescriptor(key: "cardName", ascending: true)
fetchRequest.sortDescriptors = [sortDescriptor]
fetchRequest.fetchBatchSize = 50
fetchRequest.returnsObjectsAsFaults = false
let fetchedResultsController = NSFetchedResultsController(fetchRequest: fetchRequest, managedObjectContext: self.context, sectionNameKeyPath: nil, cacheName: nil)
fetchedResultsController.delegate = self
return fetchedResultsController
}()
的UISearchBar方法
func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
block?.cancel()
var predicateArray = predicateArrayClass.arrayOfPredicates
block = DispatchWorkItem {
let predicate = NSPredicate(format: "\(self.searchPredicateName) contains[c] %@", searchText)
predicateArray.append(predicate)
self.fetchedResultsController.fetchRequest.predicate = NSCompoundPredicate(andPredicateWithSubpredicates: predicateArray)
print(self.fetchedResultsController.fetchRequest.predicate)
self.connectFetchedRequest()
DispatchQueue.main.async(execute: {
self.tableView.reloadData()
})
}
DispatchQueue.main.asyncAfter(deadline: .now() + 0.5, execute: block!)
}
我添加了MOC孩子但它没有帮助,写新的问题http://stackoverflow.com/questions/40712137/filtering-nsfetchedresultcontroller-via-searchbar-without-loading-base-pauses – Skie