加载UIWebView时不会出现Swift UIActivityindicator

Question

我正在尝试使用ActivityIndi​​cator向用户显示网站正在加载，但ActivityIndi​​cator将永远不会出现。它应该在网站加载时旋转，并在网站完成时停止并隐藏。我是否必须将指示器连接到delage或其他东西。这是我的代码全部在swift。

    //
//  WebsiteViewController.swift
//  ParseStarterProject-Swift
//
//  Created by Lucas on 1/10/16.
//  Copyright © 2016 Parse. All rights reserved.
//

import UIKit

class WebsiteViewController: UIViewController, UIWebViewDelegate {

    @IBOutlet var Active: UIActivityIndicatorView!
    @IBOutlet var webView: UIWebView!


    override func viewDidLoad() {
        super.viewDidLoad()


        let url  = NSURL(string: "http://www.google.com")!
          webView.delegate = self

        webView.loadRequest(NSURLRequest(URL: url))
        // Do any additional setup after loading the view.
    }

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



  func webViewDidStartLoad(webView: UIWebView)
  {

    Active.startAnimating()



    }

   func webViewDidFinishLoad(webView: UIWebView)
    {
        Active.stopAnimating()




    }


    /*
    // MARK: - Navigation

    // In a storyboard-based application, you will often want to do a little preparation before navigation
    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        // Get the new view controller using segue.destinationViewController.
        // Pass the selected object to the new view controller.
    }
    */

}