Question

我正在尝试从Core Data中获取一些数据并遇到了一些小问题。我可以毫无问题地获取数据。当我尝试获取特定数据（即data.fooBar）时，它会引发错误：

“'AnyObject'没有成员名称'fooBar'

如果我println(data)，则会显示fooBar确实存在数据。

我不确定为什么会这样做。我试图寻找答案并尝试了许多不同的东西，但似乎都没有。任何帮助都会很棒。谢谢。：）

    var results : Array<AnyObject> = []


    func tableView(tableView: UITableView!, didSelectRowAtIndexPath indexPath: NSIndexPath!) {

    //get the data for that storedItem
    var appDel:AppDelegate = UIApplication.sharedApplication().delegate as AppDelegate
    var context:NSManagedObjectContext = appDel.managedObjectContext!
    let req = NSFetchRequest(entityName: "storedItems")

    let name:String = results[indexPath.row].name
    req.predicate = NSPredicate(format: "name == %@", name)
    req.returnsObjectsAsFaults = false

    var tapResults = context.executeFetchRequest(req, error: nil)!

    for item in tapResults {
        println(item) //works, shows all data correctly(including subText)
        println(item.name) //works, the only one that does for some reason???
        println(item.subText) //Error 'AnyObject' does not have a member name 'subText'
    }

以下是println(item)

的结果

 println(item) <NSManagedObject: 0x7f04be60> (entity: storedItems; id: 0x7f041de0 <x-coredata://DD4F8E68-2234-46B5-B1D8-AE2F75245C63/storedItems/p1> ; data: {
alarmSound = default;
isDefault = 0;
name = "test";
sliderHours = 0;
sliderMinutes = 0;
sliderSeconds = 0;
subText = "00:00:00";

更新：根据对vacawama回答的讨论（谢谢Aaron）。如需正确解决方案，请参阅我接受的答案。

我的itemObj类

  @objc(itemObj)
  class itemObj: NSManagedObject {

        @NSManaged var name:String!
        @NSManaged var sliderHours:NSNumber
        @NSManaged var sliderMinutes:NSNumber
        @NSManaged var sliderSeconds:NSNumber
        @NSManaged var subText:String!
        @NSManaged var alarmSound:String!
        @NSManaged var isDefault:NSNumber
    }

我的AddItem VC：

    var tResults = (context.executeFetchRequest(req, error: nil))

    for item in tResults as [itemObj!] {

        println(item.name)
        println(item.subText)

    }

Answer 1

executeFetchRequest返回AnyObject的可选数组。你不应该强行打开它（这会导致崩溃）。因此，可选择解包并执行可选的强制转换（as?）以确保类型正确：

func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
    let appDel:AppDelegate = UIApplication.sharedApplication().delegate as AppDelegate
    let context:NSManagedObjectContext = appDel.managedObjectContext!
    let req = NSFetchRequest(entityName: "storedItems")

    let name:String = results[indexPath.row].name
    req.predicate = NSPredicate(format: "name == %@", name)
    req.returnsObjectsAsFaults = false

    let tapResults = context.executeFetchRequest(req, error: nil)

    if let presentResults = tapResults {
        if let castedResults = presentResults as? [MyManagedObjectSubclass] {
            for item in castedResults {
                println(item)
                println(item.name)
                println(item.subText)
            }
        }
    }
}

我还将所有var更改为let，因为它们不需要变异。

只需将MyManagedObjectSubclass替换为NSManagedObject子类。

SWIFT - ＆＃39; AnyObject＆＃39;没有会员名称＆＃39; fooBar＆＃39;

1 个答案: