I have an app with a LoginViewController as the initial view.
Note: So in appDelegate.m, self.window.rootViewController is NOT the TabBarController.
After Auth, I present the main part of the app, which has a tabbarController (identifier:tabBar) with two tabs and one tab has a navigation controller. I am using Core Data, so I need to pass MOC.
If I use,
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:#"MainStoryboard" bundle:nil];
UITabBarController *obj=[storyboard instantiateViewControllerWithIdentifier:#"tabBar"];
[obj setSelectedIndex:0];// Which tab to show first
[self presentModalViewController:obj animated:YES];
It works good visually. Now I need to pass the MOC. Read about PrepareToSegue method,created a segue (modal, Not shown in pic) from loginVC to my TargetViewController (TabBar>NavigationController1>View1), named the segue "LoginSegue" and used the following code:
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
UINavigationController *navController = (UINavigationController *)[segue destinationViewController];
View1 *devicelist = (View1 *)[[navController viewControllers] lastObject];
devicelist.managedObjectContext = managedObjectContext;
}
The TabBar does not show. How do i set the tabbar controller in this case?
I have been trying to get a grasp on getting a reference for the Modal Tabbar, but still not clear. Can some one explain in layman terms how to handle a situation like this?
I think it would be better to use a design that doesn't use a modal transition to the tab bar controller. Modal presentations are generally supposed to be for interruptions to the normal flow of the app, not for getting your main controller on the screen. There are two alternatives, that I think are better. You can leave the login controller as the initial root view controller of the window, but then switch it out for the tab bar controller (which will be the new root view controller of the window, and the login controller will be deallocated). This usually works ok, but I think in this case where you want to pass the MOC from the app delegate (I presume) to a controller in the tab bar controller, I think a second way would be better.
The second way to do this, and the way I usually do login controllers, is to have the tab bar controller be the root view controller of the window, and then present the login controller modally from the viewDidAppear method of the initial view (which would be the one you're calling View1). If you do this presentation with animation set to NO, the login controller will be the first thing the user sees:
-(void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
static int first = 1;
if (first) {
LoginViewController *login = [self.storyboard instantiateViewControllerWithIdentifier:#"Login"];
[self presentViewController:login animated:NO completion:nil];
first = 0;
}
}
The if statement is in there so the presentation doesn't happen again when you come back from the login controller (you could do something more sophisticated like having a delegate call back to View1 from the login controller indicating that the login was successful if you want, but this works).
If the login succeeds, you just dismiss the login controller, and you'll be there in your first view (if it fails, you just never dismiss it, and maybe put up a message saying the login failed).
If you go this route, then you can pass the MOC in the app delegate like this:
UINavigationController *nav = [(UITabBarController *)self.window.rootViewController viewControllers][0];
View1 *devicelist = (View1 *)nav.viewControllers.lastObject;
devicelist.managedObjectContext = managedObjectContext;
Related
Here is the scenario:
The first scene in my storyboard is a login view. It's a UIViewController. When the user is logged in, it shows the home view which is embedded in a navigation controller. I'm adding a log out functionality which should take me back to the first scene in the storyboard which is the login view. How do I do that?
Here is an image of the storyboard showing the login view -> navigation controller -> home view
This is my implementation so far. In the log out action, I clear the session, and pop to root view controller. It does not work because I am still stuck on the home view since it is the root view controller of the navigation controller. However, If I restart the app, the user is logged out and I'm left with the login view.
Code:
[self.navigationController popToRootViewControllerAnimated:NO];
// Set at beginning of storyboard
UIStoryboard *mystoryboard = [UIStoryboard storyboardWithName:#"Main" bundle:nil];
AppDelegate *app = (AppDelegate *)[[UIApplication sharedApplication] delegate];
app.loginViewController = [mystoryboard instantiateViewControllerWithIdentifier:#"loginViewController"];
Use unwind segues for that.
In your LoginViewController, declare a method with this signature
- (IBAction)unwindToLoginViewController:(UIStoryboardSegue*)segue
Go to your HomeViewController and control drag from your logout button to the Exit button at the top of your view controller window (see screenshot below), then select the unwindToLoginViewController segue. That's it!
U can pop by using navigationController.viewControllers.Get all View Controllers among navigationController,identify it and then pop.If u have pushed the segue from LoginView to HomeView
if([self.navigationController.viewControllers[0] isKindOfClass:[LoginViewController class]])
{
[self.navigationController popToViewController:self.navigationController.viewControllers[0] animated:YES];
}
Hope it helps you...
Try this answer. First you create a navigation controller. make it "is initial View Controller". After that connect login Viewcontroller as a root view controller And connect home controller with facebook button Action.
Navigation Controller -> Login Controller -> Home Controller
Your Storyboard is look like this
After that when you logout from HomeViewController then Just add this method:
-(IBAction)logOut_Action:(id)sender
{
[self.navigationController popViewControllerAnimated:YES];
}
Its working Fine. Please implement like this and let me know if you face any problem. :)
Try this:
[self.view.window.rootViewController dismissViewControllerAnimated:YES completion:nil];
I have a storyboard in my application with a navigation controller and several views. This automatically puts a navigation bar with a back button into any views that are not the root view.
However, sometimes I navigate away from this storyboard to an individual nib. I want to navigate back to the storyboard, but not necessarily to the original root view. I currently use this method to do so:
+(void) TransitionOnStoryboard:(NSString*)storyboard to:(NSString*)identifier withViewController:(UIViewController*)viewController
{
UIStoryboard *sb = [UIStoryboard storyboardWithName:storyboard bundle:nil];
UIViewController *vc = [sb instantiateViewControllerWithIdentifier:identifier];
vc.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
[viewController presentViewController:vc animated:YES completion:NULL];
}
This shows the view I want but without the navigation bar. How do I specify my navigation controller or root view, such that the app knows to put a navigation bar with a back button in?
Thanks
The answer is to leave your navigation controller underneath the view controller you add from a nib.
Present the nib as a full0-screen modal. That gets rid if your navigation bar, as desired. From that new view controller, you can push more modals, add a navigation controller, or whatever.
Note that you could do all of this and stay inside your storyboard as well.
Once you are done, dismiss the modal to reveal your navigation controller, and you are back in business with your storyboard. You can push a new view controller onto your navigation controller without animation and it should appear as the front-most VC when you pop the modal that came from a nib.
I'm sure that this isn't the ideal way to solve this problem, but it did work very nicely for me.
Essentially, I removed all the views from the view controller that had been generated since I navigated away from the storyboard, but before the current view and popped the current view. In this case, these views were of one class (CheckboxListViewController) and so could be removed quite simply as below:
+(void) navigateToMainMenu:(UINavigationController*)navigationController
{
[QuickView removeFromNavigationController:navigationController allOfViewControllerWithClass:[CheckboxListViewController class]];
[navigationController popViewControllerAnimated:YES];
}
+(void) removeFromNavigationController:(UINavigationController *)navigationController allOfViewControllerWithClass:(Class)viewControllerClass
{
NSMutableArray *keptViewControllers = [[NSMutableArray alloc]init];
for (UIViewController *viewController in navigationController.viewControllers)
if (![viewController isKindOfClass:viewControllerClass])
[keptViewControllers addObject:viewController];
navigationController.viewControllers = keptViewControllers;
}
(note- QuickView is the name of the class that contains these methods.).
Any other classes that you do not want your pop to navigate back to can be removed by calling:
[QuickView removeFromNavigationController:navigationController allOfViewControllerWithClass:[YourClassName class]];
In the navigateToMenu method.
In android, switching between activities, is fairly straightforward
you call
Intent intent = new Intent(this,NextActivity.class); <- define the next activity
startActivity(intent); <- start the next activity
finish(); < -get rid of the current activity
now in iOS i know how to do this:
UIViewController *nextviewcontroller = [[UIViewController alloc]initWithNibName:#"nextvc" bundle:nil];
[self presentViewcontroller:nextviewcontroller animated:YES completion:nil];
How do I get rid of the current view controller? so that currentviewcontroller dies after presenting nextviewcontroller ?
[self dismissViewController:YES]; doesnt seem to do the trick
the lifecycle methods viewWillDisappear and viewDidDisappear are called even if I don't call [self dismissViewController:YES];
i want "currentviewcontroller" to be removed from the memory, and from the viewcontroller stack, so that clicking "back" in "nextviewcontroller" will go to some thirdviewcontroller that was before currentviewcontroller
In iOS is different, since there's no concept of Activity and everything is more focused on the app itself (in Android you can mix activities from different apps). Therefore, there's no concept of "view controller stack".
The most similar concept is the "navigation stack" of navigation controllers, where you actually push and pop new view controller into some kind of linear navigation. A navigation bar is automatically created and populated with back buttons.
presentViewController will show your view controller modally upon the current one, but you can't thrash the presenting one since it's holding and containing ("defining context") the new one.
If you use a navigation controller for your navigation hierarchy (I don't know if you can), you can override the back button and use something like
UIViewController * prev = self.navigationController.viewControllers[self.navigationController.viewControllers.count -2 ]
[self.navigationController popToViewController:prev animated:YES]
With a modal view controller, you may try something like (I haven't tried but it may work)
[self.presentingViewController.navigationController popViewControllerAnimated:YES]
You should write one of these code into the target action of your close button.
iOS doesn't maintain a global stack of controllers in the way that Android does. Each app shows a controller at its root, and that one is responsible for showing the other controllers in the app. Controllers can display other controllers modally using presentViewcontroller:animated:completion: but the presenting controller remains underneath the presented one.
If your current controller is the root controller, then instead of using presentViewcontroller:animated:completion: you'd just do this:
self.view.window.rootViewController = nextViewController;
It's very common for the root controller to be a UINavigationController, which does manage a stack of controllers. If that is the case, and if your current controller is at the top of the stack, you'd do this:
[self.navigationController popViewControllerAnimated:NO];
[self.navigationController pushViewController:nextViewController animated:YES];
If your setup is different, you'd do something different; it's hard to say what without knowing more. But it's most likely that you'd be in the UINavigationController case.
In the viewDidAppear of your nextviewcontroller you could add :
-(void)viewDidAppear:(BOOL)animated{
[super viewDidAppear:animated];
NSArray *controllers = self.navigationController.viewControllers;
NSMutableArray *newViewControllers = [NSMutableArray arrayWithArray:controllers];
[newViewControllers removeObjectAtIndex:[controllers count]-2];
self.navigationController.viewControllers = newViewControllers;
}
There is nothing available like this in iOS but you can achieve it doing something like below
NSArray *viewControllers=[self.navigationController viewControllers];
NSMutableArray *newControllers=[[NSMutableArray alloc] init];
for(int i=[viewControllers indexOfObject:self];i<viewControllers.count;i++){
[newControllers addObject:[viewControllers objectAtIndex:i]];
}
[self.navigationController setViewControllers:[[NSArray alloc] initWithArray:newControllers]];
I have tried the method of storing all the view controllers in an array but it didn't work for me . When you try popViewController it will move to the View Controller which is last in the stack.
You can make 2 navigation controllers and switch between them and also switch between the view controllers of a particular Navigation Controller.
For eg.
You can switch between 2 Navigation Controller using the following code:
FirstNavController *fisrtView=[storyboard instantiateViewControllerWithIdentifier:#"firstnavcontroller"];
self.window.rootViewController = firstView;
}else{
SecondNavController *secondView=[storyboard instantiateViewControllerWithIdentifier:#"loginnavcontroller"];
self.window.rootViewController = secondView;
}
If your FirstNavController has 2 ViewControllers then you can switch between them using pushViewController
SecondViewController *sc = [self.storyboard instantiateViewControllerWithIdentifier:#"secondviewcontroller"];
[[self navigationController] pushViewController:sc animated:YES];
and popViewController
[self.navigationController popViewControllerAnimated:YES];
I have a tab bar controller with a navigation controller per tab. The nav controllers have view controllers. I then have a Login View Controller not connected to the tab bar controller that I call with the code below if a user needs to login or logs out.
I am seeing some strange behavior when I try to conditionally push a view controller based on if a user is logged in or not.
My logic looks like this:
if(currentUser){
}else{
LoginViewController *svc = [self.storyboard instantiateViewControllerWithIdentifier:#"Login"];
svc.hidesBottomBarWhenPushed = YES;
[self.navigationController pushViewController:svc animated:YES];
}
When the view is pushed it look as if the the Login View is pushed and another Login View is pushed on top of it.
For logout I have the same code in a segue:
if ([segue.identifier isEqualToString:#"LogoutView"]) {
[self logOut];
LoginViewController *svc = [self.storyboard instantiateViewControllerWithIdentifier:#"Login"];
svc.hidesBottomBarWhenPushed = YES;
[self.navigationController pushViewController:svc animated:YES];
}
In this instance I see the same double push and each time I click my login button it pushes another Login View. This happens infinitely. I then get the warning:
Finishing up a navigation transition in an unexpected state.
Navigation Bar subview tree might get corrupted.
When I press back in the navigation, the app crashes with the error:
NSInvalidArgumentException', reason: 'Can't add self as subview'
Am I not correctly pushing the login view controller?
Segues instantiate new controllers, and perform the transition form the source controller to the destination controller. Therefore, you should neither be instantiating the controller in code, nor pushing it with pushViewController:animated:. If the buttons (rather than the controller) are triggering the segues, then you only need to get a reference to the destination controller (segue.destinationViewController), and use that to hide the bottom bar,
-(void)prepareForSegue:(UIStoryboardSegue *) segue sender:(id) sender {
if ([segue.identifier isEqualToString:#"LogoutView"]) {
[self logOut];
LoginViewController *svc = segue.destinationViewController;
svc.hidesBottomBarWhenPushed = YES;
}
}
If you need to do this conditionally, then the segue should be connected directly from the controller, not a button. Then you need to call performSegueWithIdentifier: in some method where you have the logic to determine which (or whether a) segue should be performed.
From Home view - my RootViewController - I open up 2 ViewControllers one after another as user progresses in navigation hierarchy like so:
1) SecondViewController is pushed by button connected in my Storyboard
2) ThirdViewController is presented modally
[self performSegueWithIdentifier:#"NextViewController" sender:nil];
So, the picture is: RootViewController -> SecondViewController -> ThirdViewController
Now in my ThirdViewController I want to have a button to go back 2 times to my RootViewController, i.e. go home. But this does not work:
[self.navigationController popToRootViewControllerAnimated:YES];
Only this guy goes back once to SecondViewController
[self.navigationController popViewControllerAnimated:YES];
How can I remove both modal and pushed view controllers at the same time?
I had a similar situation, where I had a number of view controllers pushed onto the navigation controller stack, and then the last view was presented modally. On the modal screen, I have a Cancel button that goes back to the root view controller.
In the modal view controller, I have an action that is triggered when the Cancel button is tapped:
- (IBAction)cancel:(id)sender
{
[self.delegate modalViewControllerDidCancel];
}
In the header of this modal view controller, I declare a protocol:
#protocol ModalViewControllerDelegate
- (void)modalViewControllerDidCancel;
#end
And then the last view controller in the navigation stack (the one that presented the modal view) should implement the ModalViewControllerDelegate protocol:
- (void)modalViewControllerDidCancel
{
[self dismissViewControllerAnimated:NO completion:nil];
[self.navigationController popToRootViewControllerAnimated:YES];
}
This method above is the important part. It gets the presenting view controller to dismiss the modal view, and then it pops back to the root view controller. Note that I pass NO to dismissViewControllerAnimated: and YES to popToRootViewControllerAnimated: to get a smoother animation from modal view to root view.
I had the same requirement but was using custom segues between the view controllers. I came across with the concept of "Unwind Segue" which I think came with iOS6. If you are targeting iOS6 and above these links might help:
What are Unwind segues for and how do you use them?
http://chrisrisner.com/Unwinding-with-iOS-and-Storyboards
Thanks.
Assuming your AppDelegate is called AppDelegate, then you can do the following which will reset the rootviewcontroller for the app window as the view RootViewController
AppDelegate *appDel = (AppDelegate*)[[UIApplication sharedApplication] delegate];
RootViewController *rootView = [[RootViewController alloc] init];
[appDel.window setRootViewController:rootView];