ios - 仅适用于 iOS 10 的 Swift 3 中的 NSBatchDeleteRequest？

Question

所以，将我的代码迁移到 Swift 3 让我有点卡住了。似乎 NSBatchDeleteRequest 现在需要 iOS 10？我可以构建代码的唯一方法是使用以下代码片段:

func removeAllChargerData(){
    // Remove all charging data from persistent storage
    let fetchRequest: NSFetchRequest<NSFetchRequestResult> = ChargerPrimary.fetchRequest()
    let entity = NSEntityDescription.entity(forEntityName: "ChargerPrimary", in: self.secondMoc)
    fetchRequest.entity = entity
    let deleteRequest = NSBatchDeleteRequest(fetchRequest: fetchRequest)

    do {
        try self.secondMoc.execute(deleteRequest)
    } catch {
        let deleteError = error as NSError
        NSLog("\(deleteError), \(deleteError.localizedDescription)")
    }

}

但是，会出现一条警告，指出 fetchRequest() 仅在 iOS 10 及更新版本中可用。如果我按以下方式定义 fetchRequest，我会得到一个错误，因为它期望 fetchRequest 有一个 NSFetchRequestResult 参数类型:

let fetchRequest = NSFetchRequest<ChargerPrimary>(entityName: "ChargerPrimary")

Answer 1

您只需要为泛型指定正确的类型:

let fetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: "ChargerPrimary")