swift - 具有多个sortDescriptors和Bool过滤器的Swift fetchRequest

我从核心数据中提取。我有一个属性，它是一个bool，与time属性一起保存。我需要返回布尔值为真的日期数组。我不能让它工作，我要么得到一系列空日期，要么它崩溃。

func datesWithCompleteHBI() -> [Date] {

  let managedObjectContext = (UIApplication.shared.delegate as! AppDelegate).managedObjectContext
  fetchRequest.resultType = .dictionaryResultType
  fetchRequest.propertiesToFetch = ["savedTime", "harveyBradshawIndexComplete"]

  let timeSort = NSSortDescriptor(key: "savedTime", ascending: false)
  let hbiSort = NSSortDescriptor(key: "harveyBradshawIndexComplete", ascending: false)
  fetchRequest.sortDescriptors = [timeSort, hbiSort]

  let messageKey = true
  fetchRequest.predicate = NSPredicate(format: "harveyBradshawIndexSaveLevel = %@", messageKey as CVarArg)

  var dates = [Date]()
  do {

      let results = try managedObjectContext.fetch(fetchRequest) as! [[String:Date]]

      dates = results.flatMap { $0["savedTime"]}

     } catch let error as NSError {
       print("Could not fetch \(error), \(error.userInfo)")

    }

 print("hbi date array \(dates)")
 return dates
 }
}

最佳答案

如果返回aDate和aBool，则返回值不能小于cc>

let results = try managedObjectContext.fetch(fetchRequest) as! [[String:Any]]

不筛选代码中的项，而是将筛选条件添加到谓词中

fetchRequest.predicate = NSPredicate(format: "harveyBradshawIndexSaveLevel = %@ AND savedTime == TRUE", messageKey as CVarArg)

现在[[String:Date]]包含已筛选的项。

关于swift - 具有多个sortDescriptors和Bool过滤器的Swift fetchRequest，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/39687870/