ios - 将语法转换为 swift 3.0 NSFetchedResultsController

Question

我如何将我的 NSFetchedResultsController 转换为 swift 3.0，我无法让它工作....我尝试了 apple 的自动转换但它不起作用？？

我有这个:

lazy var fetchedResultsControler: NSFetchedResultsController = {
    let fetchRequest = NSFetchRequest(entityName: "Mesages")
    fetchRequest.sortDescriptors = [NSSortDescriptor(key: "timestamp", ascending: true)]
    fetchRequest.predicate = NSPredicate(format: "user.id = %@", self.friend!.id!)
    let moc = (UIApplication.sharedApplication().delegate as! AppDelegate).managedObjectContext
    let frc = NSFetchedResultsController(fetchRequest: fetchRequest, managedObjectContext: moc, sectionNameKeyPath: nil, cacheName: nil)
    frc.delegate = self
    return frc
}()

自动转换为:

    lazy var fetchedResultsControler: NSFetchedResultsController = { () -> <<error type>> in
    let fetchRequest = NSFetchRequest(entityName: "Mesages")
    fetchRequest.sortDescriptors = [NSSortDescriptor(key: "timestamp", ascending: true)]
    fetchRequest.predicate = NSPredicate(format: "user.id = %@", self.friend!.id!)
    let moc = (UIApplication.shared.delegate as! AppDelegate).managedObjectContext
    let frc = NSFetchedResultsController(fetchRequest: fetchRequest, managedObjectContext: moc, sectionNameKeyPath: nil, cacheName: nil)
    frc.delegate = self
    return frc
}()

但它不起作用，它要求我在随机位置放置分号

Answer 1

需要在括号<>内设置NSFetchRequestResult。

对于 swift 3.0:

lazy var fetchedResultsControler: NSFetchedResultsController<NSFetchRequestResult> = {
    let fetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: "Mesages")
    fetchRequest.sortDescriptors = [NSSortDescriptor(key: "timestamp", ascending: true)]
    fetchRequest.predicate = NSPredicate(format: "user.id = %@", self.friend!.id!)
    let moc = (UIApplication.shared.delegate as! AppDelegate).managedObjectContext
    let frc = NSFetchedResultsController(fetchRequest: fetchRequest, managedObjectContext: moc, sectionNameKeyPath: nil, cacheName: nil)
    frc.delegate = self
    return frc
}()