Navigation Viewcontroller not showing back button - ios

Here let me mention viewcontroller as vc.. Using navigation controller I'm moving from vc1 to vc2. and from vc2 to vc3 I'm moving programatically, using modal. And I'm returning back again programatically to vc2. But here my navigation bar back button is disappeared in vc2 and I'm not able to move back from vc2 to vc1. Navigation bar back button works before entering vc3, I mean I can move to and from between vc1 to vc2 as many times as I can, but if I once enter vc3... I can come back to vc2 and from there I cannot go back to vc1.
vc2 to vc3....
VC3 *vc3 = [self.storyboard instantiateViewControllerWithIdentifier:#"VC3"];
[self presentModalViewController:vc3 animated:YES];
vc3 to vc2.....
VC2 *vc2 = [self.storyboard instantiateViewControllerWithIdentifier:#"VC2"];
[self presentModalViewController:vc2 animated:YES];

From "vc3 to vc2" you need to come as dismissing view controller vc3.Replace your code of vc3 to vc2.....
[self dismissModalViewControllerAnimated:YES];
In your code you are again presenting vc2 on vc3 instead of dismissing v3.

Related

PresentViewController from a presentedViewController is not showing navigation bar

I have three view controllers (vc1, vc2, vc3) and two navigation controllers (nav1, nav2).
nav1 is the entry point of the storyboard.
vc1 is the rootViewController of nav1.
vc2 is the rootViewController of nav2.
nav2 is presented from vc1 through nav1.
Now when I tried to present vc3 from vc2 through nav2, navigation bar is not showing.
You need to present your controller with navigationController.
ViewController *objVC = [self.storyboard instantiateViewControllerWithIdentifier:#"viewcontrollerid"];
UINavigationController *navController = [[UINavigationController alloc]initWithRootViewController:objVC];
[self.navigationController presentViewController:navController animated:YES completion:nil];
Now, the way iOS works, it will never give you an instance of your navigation controller in a presented view controller because when you present a view controller, it is not added to the viewcontroller stack of the navigation controller.
The reason you can see the navigation controller in the other two is because your'e presenting the navigation controller itself and not view controller.

iOS: how to detect if viewcontroller appears after pop or dismiss

I have a view controller VC1 and I am doing following two operations on it:
Push another view controller VC2 from VC1's navigation controller by calling
[VC1.navigationController pushViewController: animated:YES];
Present another view controller VC3 from VC1 by calling.
UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:VC3];
[VC1 presentViewController:navController animated:YES completion:nil];
Now when I am coming from VC2 to VC1 I am calling
[VC2.navigationController popViewControllerAnimated:YES];
and from VC3 to VC1 I am calling
[VC3.navigationController dismissViewControllerAnimated:YES completion:nil];
My question is when I am coming back to VC1 how do I know that whether I am coming from VC2(by dismissing) or VC3(by popping)?
Note: VC1 is loaded as child view controller inside a parent view controller VC4.
The best way would be to have the childViewController call back to the presenting view controller. By doing this the childViewController will not need to know the implementation details of whether it was presented modally or in a navigation stack etc.
With blocks it would look something like
#interface VC2 : UIViewController
#property (nonatomic, copy) void (^completion)(VC2 *viewController);
#end
You would set this block up something like this
VC2 *viewController = VC2.new;
viewController.completion = ^(VC2 *viewController) {
[viewController.navigationController popViewControllerAnimated:YES];
};
[VC1.navigationController pushViewController:viewController animated:YES];
Now where you was previously calling
[VC2.navigationController popViewControllerAnimated:YES];
You instead call
self.completion(self);
You put any logic you want to be associated with coming back from a specific viewController inside the completion handler

poptorootviewcontroller and dismiss to mainViewController

i am new to IOS .
My question is, i have some view-controllers as NavigationController,mainVC, VC1, VC2, VC3, CameraVC. In cameraVC i have a done button having action doneClicked. These all View-Controller are pushed in NavigationController. VC1 is presented, not pushed in nav-controller. doneClicked function implemented poptorootviewcontroller. when i click on done button it let me to VC1 but not the mainVC. Is there any way so i can pop all view controller to VC1 and after this automatically dismiss VC1 to mainVC.
Make your MainVC as root view controller and in the IBAction of done button use the code to pop to MainVC.
[self.navigationController popToRootViewControllerAnimated:YES];
Hope it helps.
To pop view controllers
[self.navigationController popToRootViewControllerAnimated:YES];
and to dismiss presented view controller
[self dismissViewControllerAnimated:NO completion:nil]
[self.navigationController setViewControllers:#[mainVC]];
I think this code will work on your situation. iOS Developer Library:
Replaces the view controllers currently managed by the navigation controller with the specified items.
- (void)setViewControllers:(NSArray *)viewControllers
animated:(BOOL)animated
source
you must do this after dissmiss present view controller. Use delegate
Now let's think your navigation stack is empty and your root is mainVC. you want to present VC1 that's ok just present it. But you should give a delegate to mainVC to what's gonna happen after dissmissing VC1. For example you present VC1 from mainVC. And you want to push VC2 after dissmiss VC1. That's ok just in mainVC has a delegate so in this method
[self.navigationController pushViewController:VC2];
Present views does not affect your navigation stack. It's not in your stack. so everytime you dismiss it from a controller you should give an delegate to that controller to what will happen after dissmissing.
Try it.
Hope it helps.

Transition between two viewControllers presented by rootView controller

My use case as follows:
VC1 - Root Controller
VC2 & VC3 are different view controllers
VC1 is delegate of VC2
VC1 presents VC2
Then as delegated, VC1 dismiss VC2
Right after dismiss VC2, VC1 presents VC3
In the last step my transition goes bad as after dismissVC2 and beforePresentVC3, VC1 is visible during transition
How can I fix this problem or is it even possible??
NOTE: I want VC1 in window herirarchy so that I can go to VC1 from VC3
I think you're getting into some trouble with no sense. You could easily have a hidden navigationController and create and stack every VC and then move around with
self.navigationController popToViewController: animated:
or
self.navigationController pushToViewController: animated:
then you could move from 1 to 3, or 3 to 1 with no problem. If you created all the VCs and are available to access from any of the 3 vcs

Interface Builder IB - Navigation Controller, skipping a view

Hello I am new to iOS and have a question about navigating through my views.
I am using IB wiring up the PREVIOUS and NEXT buttons in the nav bar that pushes my views. This all works fine. However I am having trouble finding out where exactly what I need to do or where I need to place the code so I can skip over a view. To simplify my situation...
-I have 1 Nav Controller and 4 View Controllers named VC1, VC2, VC3, VC4. Each VC has a .H/.M
-Starting from VC1, they follow one after the other.
Say I want to skip VC3 and jump right to VC4 based on a setting in VC2. Where would I put the code to do this? Would I need to unhook the IBAction method from the NAV buttons at VC3?
I do apologize if this has been covered before. If there is a tut or if you know of a post that answers this, please let me know. I did do a search but the search was returning generic posts probably due to me using the wrong terminology.
Thanks in advance.
A couple of thoughts:
If you want to push from VC2 to either VC3 or to VC4, rather than having VC3 immediately push to VC4 in special cases, I think it's better to just have VC2 push directly to the appropriate view controller. Thus you might have an IBAction in VC2 that would do this for you:
- (IBAction)pushToNext:(id)sender
{
BOOL skipToVC4 = ... // put in whatever logic you'd use to bypass VC3 and go directly to VC4
UIViewController *nextController;
if (skipToVC4)
{
nextController = [self.storyboard instantiateViewControllerWithIdentifier:#"VC4"];
// obviously, if using NIBs, you'd do something like:
// nextController = [[ViewController4 alloc] initWithNibName:#"VC4" bundle:nil];
}
else
{
nextController = [self.storyboard instantiateViewControllerWithIdentifier:#"VC3"];
}
[self.navigationController pushViewController:nextController animated:YES];
}
This way, when you pop back from VC4, you'll pop back directly to the appropriate view controller (e.g. if you pushed from VC2 to VC4, when you pop, you'll pop right back to VC2 automatically.
And, obviously, if you're using storyboards, rather than manually invoking pushViewController, you could have two segues from VC2 (one to VC3 and one to VC4), give them appropriate identifiers, and then just invoke performSegueWithIdentifier to segue to the appropriate view controller. But the idea is the same: You can define an IBAction that performs the appropriate segue depending upon whatever logic you so choose.
You say that you have "PREVIOUS and NEXT buttons in the nav bar that pushes my views", I wonder about your "PREVIOUS" button. Is that doing a popViewControllerAnimated? Generally, a "NEXT" button will push to a new view controller, but the "PREVIOUS" button should not push to the previous view, but pop back to it. If you don't pop back, you can end up with multiple instances of some of your prior view controllers. Thus, the "PREVIOUS" button should be linked to an IBOutlet that does something like:
- (IBAction)popToPrevious:(id)sender
{
[self.navigationController popViewControllerAnimated:YES];
}
When popping back, you'll obviously pop back to the view controller that you pushed from. If you want to skip a few of the view controllers as you're popping back in iOS versions prior to 6.0, you would use popToViewController or popToRootViewControllerAnimated. For example, let's say that you pushed from VC1 to VC2, to VC3, to VC4. If you want to pop back from VC4 all the way to VC1, you would hook up and IBAction in VC4 like:
- (IBAction)popToRoot:(id)sender
{
[self.navigationController popToRootViewControllerAnimated:YES];
}
Or, if you wanted to pop back from VC4 to VC2, you would
- (IBAction)popToVC2:(id)sender
{
for (UIViewController *controller in self.navigationController.viewControllers)
{
if ([controller isKindOfClass:[ViewController2 class]])
{
[self.navigationController popToViewController:controller animated:YES];
return;
}
}
}
You can avoid this iteration through the navigationController.viewControllers if you passed a reference of VC2 to VC3 and then again to VC4, but sometimes the above technique is easier.
By the way, if you're supporting iOS 6 and above, only, and are using storyboards, you can also use unwind segues, which are a more elegant way of popping back to a particular view controller. But it's not clear whether (a) you're using storyboards; and (b) you're supporting iOS 6 and above only, so I'll refrain from a discussion of unwind segues at this point.
First:
Show us some code, where you are pushing new view controllers, maybe your whole navigation controller code
Second (Solution):
I assume:
Your prev/next buttons are linked to your navigationController class
you have the appropriate methods (prevPressed:/nextPressed:), which are called, when you click one of the buttons
I can help you with the following:
you know which controller is visible at the moment with the visibleViewController #property
each time you click on a button in the navBar you can ask the visibleViewController which next/previous view controller should be pushed/popped
Best solution would be, if all of your controllers VC1/2/3/4 are a subclass of a viewController class, which defines a method in it's interface:
- (Class)nextViewControllerClass;
- (Class)previousViewControllerClass;
and in the implementation:
- (Class)nextViewControllerClass {
return [VC4 class];
}
- (Class)previousViewControllerClass {
return [VC1 class];
}
And in your navigationController code the do this:
- (IBAction)next:(id)sender {
UIViewController *nextViewController = [[[self.visibleViewController nextViewControllerClass] alloc] init];
[self pushViewController:nextViewController animated:YES];
}

Resources