Making a UINavigationController go back via code - iphone

The UINavbarcontroller will go back to the previous VC when i press the Left button on the NavBar. Works as expected.
I also need to force the screen to go back from another button, so was wondering is there something i can call to make this happen? I dnt see any method attached to UINavbarController docs for this.

try popViewController:
[self.navigationController popViewControllerAnimated:YES];

Try looking at the UINavigationController docs instead, it's the fourth of 8 instance methods:
popViewControllerAnimated:
Pops the top view controller from the navigation stack and updates the
display.
- (UIViewController *)popViewControllerAnimated:(BOOL)animated

Related

Pushed ViewController is "greyed out" cannot intact with it

Im relatively new to iOS programming and have been making a recipe based app for the iPad. I've looked around at a lot of answers and can't seem to solve my problem so ill explain how my app is laid out.
Navigation controller -> ViewController -Modal segue -> PreviewViewController -modal segue -> Navigation Controller -> RecipeViewController
Within my RecipeViewController i have a button that when pressed i want it to go back to the "home" screen which for these purposes is the "ViewController".
Here is the code for the button action in "RecipeViewController":
- (IBAction)homeB:(id)sender {
ViewController* viewController = [[ViewController alloc]init];
[self.navigationController pushViewController:viewController animated:YES];
}
However, when i press this button the ViewController is displayed, but the screen is greyed out and i can have no interaction with the screen. I can't post an image of what the screen looks like as i don't have enough reputation yet but i will update it when i can.
I have tried other ways of displaying it such as connecting a segue in the storyboard between the button and the "ViewController" and then activating the segue when the button is pressed. But this messes up other parts of my code as i have to re allocate and initialise the home screen. Would appreciate any help as to why it is coming up with the greyed out screen that cannot be interacted with.
Also just some more notes:
self.navigationController
does not return nil so it is seen, and no errors are displayed when the button is pressed.
Thanks
If you're really doing segues, then I presume this was made in a storyboard. If that's the case, then you should use an unwind segue to get back to ViewController. You do this by adding an IBAction in ViewController that looks like this:
-(IBAction)comingBackFromRecipe:(UIStoryboardSegue*)sender {
NSLog(#"I'm back");
}
The important point is that the sender type be UIStoryboardSegue. Then in IB, in the RecipeViewController, you control drag from your button to the green "Exit" icon at the bottom of the controller. When you let go, you should see the method that you wrote in ViewController -- connect it to that. This will get you back to the same instance of ViewController that you started with.
It's hard to tell without seeing a screenshot, but from what i understand, if you want to go back to the home screen, you shouldn't be pushing a new view controller (unless you really want to add it to the stack?)
To go back to the "home" screen, you should try this:
[self.navigationController popToViewController:viewController animated:YES];
or if your home screen is the root, simply use this:
[self.navigationController popToRootViewControllerAnimated:YES];
Thanks for the responses everyone, i figured out my problem though. My structure was wrong and i realised that i didn't need to have another navigation controller for the Recipe view Controller as i wasn't pushing anywhere from there. So incase anyone else has a similar problem my structure is now as follows:
Navigation Controller -> View Controller -Modal Segue -> PreviewViewController - ModalSegue -> RecipeViewController
I removed the Navigation controller between PreviewViewController and RecipeViewController. This means that they are all modal view controllers. So to get back from the RecipeViewController to the home screen which is "ViewController" i just needed to dismiss the hierarchy of modal views with the following code:
UIViewController * parent = self.presentingViewController;
[parent.presentingViewController dismissViewControllerAnimated:YES completion:nil];
I went back two stages so that both the PreviewViewController and the RecipeViewController where dismissed.
Works great now, thanks for the help anyway everyone.

Accesing the Views in iPhone

I implemented 4 views in AppDelegate depends on requirement it will call the view.I called second(example) view then I pushed to the new view again I pushed to the other new view.I want to go back to the second(example) view. I implemented the code like this [self.navigationController popToRootViewControllerAnimated:YES]; but it is poping to previous view and again it go back to the second(example) view. Can any one tell me how it goes directly to the second(example) view.
Thanks in advance.
Instead of using popToRootViewController you need to use popToViewController like bellow
self.navigationController popToViewController:secondViewObj animated:YES];
You should use
popViewControllerAnimated:animated]
or
popToViewController:yourVC animated:animated]
Use [pushViewController:obj animated:NO].....
Though this will not pop your view, but it will push your view to obj that is object of FirstView.
This will simply work as you want, may be not technical way...:)

black bar as the view fades when I am using navigation controller

I'm writing my first iPhone app and I am trying to figure out how to have a MasterView and DetailsView like in the example. However, instead of using a TableView, I want to use a button on the MasterView to go to the SignUpView. I want the MasterView to NOT have a navigation bar but the SignUpView needs to have one.
I have tried putting a NavigationController into the MasterView using the interface builder. This doesn't seem to do anything at all ... I.e. I make the following call:
[self.navigationController pushViewController:signUpViewController animated:YES];
And nothing happens. The SignUpView is never shown.
So then I declared a NavigationController in the AppDelegate. The above call in the same function that it was in before (button handler, button is in MasterView) works now! It takes me to the SignUpViewController.
however, the issue is, when I press back on the navigation bar in the sign up view, the navigation bar shows up again in the MasterView. I tried to set
self.navigationController.navigationBarHidden = YES;
in viewDidLoad and viewDidAppear, but that causes a black bar to appear in the transition from SignUpView to MasterView.
I tried to not set it in one of the two, and that causes the animation to go smoothly, but the navigation bar shows up in the MasterView.
I feel like this should be pretty simple to do ... but I'm at my wits end trying to figure this out. Some help would be really appreciated!
Thanks.
Probably not the answer to your question, but just a small suggestion. In the many apps that I have come across, a sign-up/sign-in view is generally displayed as a modal view (on top of your master view) with a 'cross' in the top-right corner to dismiss it. Probably it results in a better user experience.
Also, did you try self.navigationController.navigationBarHidden = YES; in the MasterView's viewWillAppear ?
HTH,
Akshay
I had this problem too, until I discovered setNavigationBarHidden. You will probably want to use these in viewWillAppear/viewWillDisappear or viewDidAppear/viewDidDisappear. You don't want to call this in viewDidLoad because that is only called once when the view is initialized, not every time it appears.
To hide:
[self.navigationController setNavigationBarHidden:YES animated:YES];
To show:
[self.navigationController setNavigationBarHidden:NO animated:YES];

Keep new view in a tab when switching to another tab

This is the situation:
I have a tab bar with 2 tabs. Tab01 and Tab02.
In Tab01 I have a button which pushes repVC:
repVC.modalTransitionStyle = UIModalTransitionStyleCoverVertical;
[self presentModalViewController:repVC animated:YES];
[(UIViewController *)[tabController.viewControllers objectAtIndex:0] setView:repVC.view];
[repVC release];
Inside repVC I have another button which pushes an MFMailComposerViewController:
MFMailComposeViewController *mail = [[MFMailComposeViewController alloc] init];
[self presentModalViewController:mail animated:YES];
[mail release];
The problem is: when mailView is shown(in Tab01) and I click Tab02, then back to Tab01, the mailView is hidden and even if I click the email button again, the view won't be presented.
So what I have is: Tab01.view -> repVC.view -> mail.view
For repVC, I use this line when I push the view so that even if I go switch tabs, that view will still be activated:
[(UIViewController *)[tabController.viewControllers objectAtIndex:0] setView:repVC.view];
But I can't do the same for mail because tabController is declared in another class which I cannot import. So I can't access the tabController and set the view for Tab01.
Hope the edit helped the understanding.
Hmm,
I still would suggest to use a Navigationcontroller. Would make things way easier, is conform to apple guidelines and suggestions and is pretty fast implemented. (Just create a Navigationcontroller, put the View of Tab1 as main view and hand it over to the TabbarController. Then for the mailView use [self.navigationController pushViewController:mail animated:YES]; Then the navcontroller "saves" the present view for you when u switch tabs)
But if for some Reason you have to use a modalViewcontroller you could either just deactivate the tabbar while the ModalView is shown or try to implement a switch or a simple if...else case in your ViewWillAppear where u check what screen to load.
Then Clean out the Window and load the right screen.
Hope you get the idea of what I mean, sometimes my way of writing seems to confuse people. ^^
A little more information would be great.
How did u set up your TabbarController?
How do u push the new view? Within a UINavigationController? If not, then do it with a navController, he should save the actual state of view and your problem should be solved.
If u already use a navController please post your ViewDidLoad and ViewWillAppear of the Viewcontroller of Tab 1
As #Amandir points out you could probably solve your problems by using a UINavigationController. I get a feeling that you are trying to abuse the modal view controller concept a bit and that's why it doesn't work as you expect. When you use presentModalViewController:animated: the intention should be that you are displaying a view that is modal, i.e. the user must interact and dismiss the modal view before she can continue.
What the paragraph above means that when you present a modal view controller it shouldn't be possible to use the tab bar. Since you are using the word push I'm guessing that you would like change the view of Tab01 while still being able to use the functionality of the tab bar. The problem is that there isn't any built-in method of pushing view controllers besides UINavigationController. persentModalViewController:animated: should only be used in case where you want a modal view, which on the iPhone means a full screen view.
The easiest way would probably be to use an UINavigationController and hide the navigation bar. Then you would get the functionality I think you are after. The other option is to manually add and remove sub views.
[self.view addSubview:repVC.view];
and
[repVC.view removeFromSuperview];
[self.view addSubview:mail.view];
You can use block animations if you want some fancy transitions.

iPhone Development, How to Programmatically Call a NavigationController back button from another tab?

Here's the setup:
I have a tab bar controller with two tabs. There is a navigation controller on top the second tab, so that I can view details from a table.
On tab #1, I have a button. When this button is pressed, it switches the selected tab over to tab #2.
My problem is this: Let's say I go to tab #2, then I select a line from my table to view the detailed information. Then, instead of hitting the "back" button to return to the base view, I select tab#1. Then I press my button. Tab#2 loads, but it is still showing the detailed view, instead of the table view that I want.
I know how to programmatically press the button.
[self.navigationController popViewControllerAnimated:YES];
But how would I do that when the button pressed method is inside the class for tab#1, which knows nothing of tab#2's navigation controller?
Hope that makes sense. Thanks in advance for any help!
Okay, I finally got it to work. The solution that was suggested gave me a good jumping off point. Here is the code that finally worked for me:
ARFinderAppDelegate appDelegate = (ARFinderAppDelegate)[[UIApplication sharedApplication] delegate];
[appDelegate.booksNavigationController popViewControllerAnimated:YES];
self.tabBarController.selectedIndex = 1;
I had to access the class that contained the NavigationController through an instance of my application delegate. I also had to remove the "objectAtIndex:1" because my application would crash.
Thanks for all the help, this has been a great learning experience for this iPhone development newbie!
use your delegate singleton.
[[delegate.tabBarController.viewControllers objectAtIndex:tab2Index] popViewControllerAnimated:YES];