错误：找不到接受提供的参数的“标题”的重载 [英] Error: Could not find overload for 'title' that accepts the supplied arguments

问题描述

当前，我有一个名为 Folder 的NSManaged对象的子类，其属性为<$ c $ item $ c> NSSet 。我有一个返回 NSMutableArray 的函数，我试图在表视图中显示数据（然后重新排列表中显示的顺序）。

Currently I have a subclass of NSManaged object called Folder with property called item that is of type NSSet. I have a function to return a NSMutableArray and I am trying to display the data in a tableview (and then rearrange the order displayed in the table).

class Folder: NSManagedObject {

@NSManaged var title: String
@NSManaged var date: NSDate
@NSManaged var item: NSSet

func itemMutableArray() -> NSMutableArray {
    return NSMutableArray(array: (item.allObjects as! [Checklist]).sorted{ $0.date.compare($1.date) == NSComparisonResult.OrderedAscending } )
}

TableViewController：

TableViewController:

 var itemMutableArray: NSMutableArray!
 itemMutableArray = folder.itemMutableArray() 

 cell.textLabel?.text = itemMutableArray[indexPath.row].title //Error

不幸的是，使用此功能时，这会在我的表视图中返回错误。

Unfortunately this returns an error in my tableview when using this function.

错误找不到接受提供的参数的'title'的重载

Error could not find overload for 'title' that accepts the supplied arguments

最终我正在尝试什么要实现的是显示数据并移动单元格以更改NSSet的顺序。

Ultimately what I am trying to achieve is to display the data and move the cells around to change the order of the NSSet.

 table.didMoveCellFromIndexPathToIndexPathBlock = {(fromIndexPath: NSIndexPath, toIndexPath: NSIndexPath) -> Void in

  let delegate:AppDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
  let context: NSManagedObjectContext = delegate.managedObjectContext!

  context.deleteObject(self.itemArray[indexPath!.row] as NSManagedObject )  

  self.itemArray.exchangeObjectAtIndex(toIndexPath.row, withObjectAtIndex: fromIndexPath.row)

 }

PS：最初我有个函数可以返回对象数组但是我无法修改NSSet的顺序，因为它们没有顺序。

PS: Originally I had a function to return an array of the object but I was unable to modify the order of the NSSet as they are not ordered.

func itemArray() -> [Item] {
    let sortDescriptor = NSSortDescriptor(key: "date", ascending: true)
    return item.sortedArrayUsingDescriptors([sortDescriptor]) as! [Item]
}

有人对我目前的错误之处有任何建议吗？

Does anybody have any suggestions with where I am currently going wrong ?

推荐答案

表达式 itemMutableArray [indexPath.row] .title 是因为您已键入 itemMutableArray 作为NSMutableArray，所以 itemMutableArray [indexPath.row] 是AnyObject。因此，Swift没有理由相信此东西具有 title 属性。您需要将其强制转换为具有 title 属性的 （尽管如果可能的话，最好完全避免使用NSMutableArray，这样会更好） ，因为Swift数组是可变的。）

The problem with the expression itemMutableArray[indexPath.row].title is that, because you have typed itemMutableArray as an NSMutableArray, itemMutableArray[indexPath.row] is an AnyObject. Thus, Swift has no reason to believe that this thing has a title property. You need to cast it to something that does have a title property (though it would be much better to avoid the use of NSMutableArray completely, if possible, since a Swift array is mutable).

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