swift3中的编译错误：“ AnyObject”不是“ NSObject”的子类型

Question

I am facing with the following error during compilation based on Swift 3.

class DetailViewController: UIViewController {

      @IBOutlet weak var detailDescriptionLabel: UILabel!


      var detailItem: AnyObject? {
        didSet {
            // Update the view.
            self.configureView()
        }
      }

      func configureView() {
        // Update the user interface for the detail item.
        if let detail: AnyObject = self.detailItem {
            if let label = self.detailDescriptionLabel {
                label.text = detail.valueForKey("timeStamp")!.description
            }
        }
      }

      override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        self.configureView()
      }

      override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
      }


    }

Error:

/.../DetailViewController.swift:27:33: 'AnyObject' is not a subtype of 'NSObject'

Answer 1

if let detail: [String: AnyObject] = self.detailItem {
        if let label = self.detailDescriptionLabel {
            label.text = detail.valueForKey("timeStamp")!.description
        }
    }

And if detailItem is for storing JSON objects, you'd better cast it to dictionary at the beginning. As if the variable is cast as AnyObject , the compile will keep prompting errors as it simply cant handle it (for your case, AnyObject class does not have valueForKey function).

Answer 2

I just changed it to this. Then it fixed.

label.text = (detail.value(forKey: "timeStamp") as! NSObject).description