Swift实战-小QQ(第3章):QQ主界面布局

 //用mainContentView装下MainTab
        var mainTabVC: UITabBarController! = self.storyboard!.instantiateViewControllerWithIdentifier("MainTabViewController") as UITabBarController

        mainContentView.addSubview(mainTabVC.view)

 override func viewDidLoad()
    {
        super.viewDidLoad()
        
        //左侧显示头像
        var photoView:UIImageView=UIImageView(image: UIImage(named: "AppIcon-160x60@2x.png"))
        photoView.frame=CGRectMake(0, 0, 40, 40)
        var photoItem:UIBarButtonItem=UIBarButtonItem(customView: photoView)
        self.navigationItem.leftBarButtonItem=photoItem
        //
    }