如何将 FetchedResultsController 限制为给定日期的对象

Question

我正在尝试创建一个 UITableView 来填充选定日期（特别是 yesterday、today 和 tomorrow）的对象。在我的 CoreData 模型中，所讨论的实体是属性 date with typeDate`.

为了获得 yesterday、today 和 tomorrow，我这样做（按照 this WWDC session 的规定）：

var today = Date()
var yesterday = calendar.date(byAdding: .day, value: -1, to: self.date)
var tomorrow = calendar.date(byAdding: .day, value: 1, to: self.date)

并执行：

today = calendar.startOfDay(for: today)
yesterday = calendar.startOfDay(for: yesterday)
tomorrow = calendar.startOfDay(for: tomorrow)

获得所有日期后，我不知道该怎么做。目前我的获取结果控制器看起来像：

    lazy var fetchedResultsController: NSFetchedResultsController<Entry> = {

        let fetchRequest: NSFetchRequest<Entry> = Entry.fetchRequest()

        // Configure Fetch Request
        fetchRequest.sortDescriptors = [NSSortDescriptor(key: "name", ascending: true)]

        // Create Fetched Results Controller
        let fetchedResultsController = NSFetchedResultsController(fetchRequest: fetchRequest, managedObjectContext: app_delegate.persistentContainer.viewContext, sectionNameKeyPath: nil, cacheName: nil)

        // Configure Fetched Results Controller
        fetchedResultsController.delegate = self

        return fetchedResultsController
}()

如何将 fetchedResultsController 限制为这些日期之一，如果可能的话，我会使用 Calendars 方法来做到这一点：isDateInToday()?

Answer 1

向提取请求添加谓词。

request.predicate = NSPredicate(format: "date > %@ && date < %@", 
   today as NSDate, tomorrow as NSDate)

如何将 FetchedResultsController 限制为给定日期的对象

How to restrict FetchedResultsController to objects in a given day

core-data

nsfetchedresultscontroller

ios