Swift: how to show a tab bar controller after a lo

问题:

I have seen many posts similar to this here but they are all about Objective-C while I am developing my app in Swift. As you can see from the image I have a login screen view and I correctly implemented the login mechanism.

Now I would like that when the login has succedeed, then the tab bar controller is showed. In my login view controller I have this function for login:

var finalURL:NSString = "\(Settings.webServerLoginURL)?username=\(username)&password=\(password)"

        LoginService.requestLoginWithURL(NSURL(string: finalURL as String)!, completionHandler: { (success) -> Void in
            if (success) {
                NSLog("Login OK")

                /* Scarica dal database i tasks di LoggedUser.id */
                /* Redirect al tab HOME dell'applicazione dove si mostrano il numero di task
                di quell'utente ed in cima "BENVENUTO: name surname" */


            }

            else {
                self.alertView.title = "Autenticazione fallita!"
                self.alertView.message = "Username o passowrd."
                self.alertView.delegate = self
                self.alertView.addButtonWithTitle("OK")
                self.alertView.show()
            }

So I think that I should show tab bar controller after

NSLog("Login OK")

but I don't know how. I am a beginner of Swift/XCode...if you can explain me. Thanks to all who have read.

回答1:

To show tab bar controller from Login page, connect the Login page and TabbarController with a Show segue and give it an identifier in attributes inspector (Say "mySegueIdentifier").

To add segue, just right click and drag from Login view controller to TabbarController.

In successful Login you can simply call "performSegueWithIdentifier" method as follows

self.performSegueWithIdentifier("mySegueIdentifier", sender: nil)

In your case you call it after this line.

NSLog("Login OK")

If you don't want to navigate from Login page to TabbarController, you can also set it as rootViewController after successful Login. To do this, set an identifier to TabbarController (Say "myTabbarController")

 let appDelegate = UIApplication.sharedApplication().delegate! as! AppDelegate

 var initialViewController = self.storyboard!.instantiateViewControllerWithIdentifier("myTabbarControllerID") as! UIViewController
 appDelegate.window?.rootViewController = initialViewController
 appDelegate.window?.makeKeyAndVisible()

Edit:

Swift 3

 let appDelegate = UIApplication.shared.delegate! as! AppDelegate

 let initialViewController = self.storyboard!.instantiateViewController(withIdentifier: "myTabbarControllerID") 
 appDelegate.window?.rootViewController = initialViewController
 appDelegate.window?.makeKeyAndVisible()

Happy coding.. :)

回答2:

I ran into this same issue when trying to segue from a controller I used for touchID to a TabBarController. By making the segue in an async block I resolved the issue.

dispatch_async(dispatch_get_main_queue(), {
    self.dismissViewControllerAnimated(false, completion: {})
    self.performSegueWithIdentifier("authnToAppSegue", sender: nil)
})

回答3:

Give your tab bar controller a StoryboardID (say "tabbar") and push it just like a normal UIViewController:

let nextViewController = self.storyboard?.instantiateViewController(withIdentifier: "tabbar") as! UIViewController

self.navigationController?.pushViewController(nextViewController, animated: true)

回答4:

func setTabBarVisible(visible:Bool, animated:Bool) {

//* This cannot be called before viewDidLayoutSubviews(), because the frame is not set before this time

    // bail if the current state matches the desired state
    if (tabBarIsVisible() == visible) { return }

    // get a frame calculation ready
    let frame = self.tabBarController?.tabBar.frame
    let height = frame?.size.height
    let offsetY = (visible ? -height! : height)

    // zero duration means no animation
    let duration:NSTimeInterval = (animated ? 0.3 : 0.0)

    //  animate the tabBar
    if frame != nil {
        UIView.animateWithDuration(duration) {
            self.tabBarController?.tabBar.frame = CGRectOffset(frame!, 0, offsetY!)
            return
        }
    }
}

func tabBarIsVisible() ->Bool {
    return self.tabBarController?.tabBar.frame.origin.y < CGRectGetMaxY(self.view.frame)
}

// Call the function from tap gesture recognizer added to your view (or button)

@IBAction func tapped(sender: AnyObject) {
    setTabBarVisible(!tabBarIsVisible(), animated: true)
}

回答5:

Call the Tabbarcontroller from any controller By below Code, default first item is selected

    let storyBoard : UIStoryboard = UIStoryboard(name: "Main", bundle:nil)

    let nextViewController = storyBoard.instantiateViewController(withIdentifier: "HomeTabBar") as! UITabBarController

    self.navigationController?.pushViewController(nextViewController, animated: true)