问Xcode不识别Timer()- Swift 3

EN

import UIKit

class ViewController: UIViewController {

    let emptystring = String()

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        var time = Timer.scheduledTimer(timeInterval: 8.0, target: self, selector: #selector(changeview), userInfo: nil, repeats: false)
    }

    func changeview (){
        self.performSegueWithIdentifier("GoToMain", sender: self)
    }

    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        if (segue.identifier == "GoToMain"){
            let destination = (segue.destinationViewController as! UINavigationController).viewControllers[0] as! SecondView
            destination.emptyString = emptystring
        }
        print("Segue Performed")
    }

}