Swift代码，app上没有webview

Question

我是xcode和swift的新手

我正在使用此代码为自己创建一个webview应用程序，该应用程序加载了启动器屏幕，但随后它的空白，网站无法加载。我错过了什么？

import UIKit
import WebKit

class ViewController: UIViewController {
    @IBOutlet weak var myWebView: UIWebView!


    var webview: WKWebView?

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        let url = NSURL (string: "http://www.gunchester.com");
        let requestObj = NSURLRequest(URL: url!);
        myWebView.loadRequest(requestObj);
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }

}