Jumping between views in Navigation controller - ios

I need to jump between view controllers. For example:
View1: First screen (Just logo)
View2: Download Screen
View3: First app screen (Some Buttons)
View4-View(N): some app screens
When user enters app the app goes to View1->View2 (downloads stuff)->View 3->View4->View5
Then user wish to go to First app screen (View3) he does:
NSArray *array = [self.navigationController viewControllers];
[self.navigationController popToViewController:[array objectAtIndex:2] animated:NO];
The first time user enters the app it goes: View1->View3 (The download screen no longer needed), and I have different push segue to go to View3 so lets assume the user goes to: View1->View 3->View4->View5, now he wishes to go back to View3, so the function:
NSArray *array = [self.navigationController viewControllers];
[self.navigationController popToViewController:[array objectAtIndex:2] animated:NO];
Will return him to View4, and this is WRONG. How can I solve it?

Well if you are using storyboards , what you can do is set your uiviewcontrollers' storyboard id and use it for popping and pushing your views.
Lets say your Storyboards name is MainStoryboard.storyboard
UIStoryboard* sb = [UIStoryboard storyboardWithName:#"MainStoryboard"
bundle:nil];
SettingsListViewController *settingsVC = [sb instantiateViewControllerWithIdentifier:#"SettingsListViewController"]; // #"SettingsListViewController" is the string you have set in above picture
[self.navigationController popToViewController:settingsVC animated:YES];
Above solution should work for you , but If I were you I would change the structure of my app , you say :
View1: First screen (Just logo)
View2: Download Screen
Since View1 is just logo and View 2 is also a view that you skip, you can remove them from navigation controller and make View3 your navigation controller's root view controller and when you need view1 and view2 present them as Modal View Controllers,
when you are done with them lets say; user successfully loaded the app dismiss logo screen and present Download Screen if download successful then dismiss it.
So your View3 Will be there as root view controller, lets say your at View(n) you want to go to home screen which is View3 all you need to do is call
[self.navigationController popToRootViewControllerAnimated:NO];
When you are on view(n) and want to pop to view(n-1) just use
[self.navigationController popViewControllerAnimated:YES];
good luck,

I always use this, and it will work fine in your case. In fact the following line of code is copied to my "Notes" for quick copy/paste.
Be sure to import your ViewController.h file, if not.
for (UIViewController *viewController in self.navigationController.viewControllers) {
if([viewController isKindOfClass:["your ViewController" class]]) {
[self.navigationController popToViewController:viewController animated:NO];
}
}

In the second sequence your navigation stack changes and view3 would be at index 1. so
[[self.navigationController popToViewController:[array objectAtIndex:1] animated:NO];
would be the right way of doing it.

according to your sitation use directly name of viewController
create instance of your viewController,like this
i supposed here that your viewController name is-view3Controller
View3Controller view3Controller=[[View3Controller alloc]init];
[self.navigationController popToViewController:#"view3Controller" animated:NO]
or if you are using storyboard then
View3Controller view3Controller=[self.storyboard instantiateViewControllerWithIdentifier:#"view3Controller"];
[self.navigationController popToViewController:#"view3Controller" animated:NO]

It sounds like View 2 is not being added to your view controllers array at run time, possibly because of the segue you've created.
Try removing the segue that transitions from View 1 > View 3 and pushing the user past View 2 without animating, as your application's logic requires it:
// If the user needs to skip ahead to view 3, conditionally push view 2 and view 3 without animating
[self.navigationController pushViewController:viewController2 animated:NO];
[self.navigationController pushViewController:viewController3 animated:NO];
Alternatively if you left the segue in place could you not look at the size of the UINavigationController viewControllers property and "guess" based on the size whether or not you skipped View 2? If you did then you can adjust the popToViewController method to pop to the correct index. This is, admittedly less elegant and brittle if you need to skip other views as well.
// Check length of viewController array with 'N' views (pseudo code)
if (self.navigationController.viewControllers.length == N-1)
// View 2 was ignored: pop to objectAtIndex:1
else
// View 2 was included: pop to objectAtIndex:2

If I understood you correctly, your view3 has special view controller, so you can use such code:
NSArray *VCs = [self.navigationController viewControllers];
for (UIViewController *VC in VCs)
{
if ([VC isKindOfClass:[**YOUR-VIEW-CONTROLLER** class]]) {
[self.navigationController popToViewController:VC animated:NO];
}
}
It's simple and it works!

for (UIViewController* controller in self.navigationController.viewControllers) {
if ([controller isKindOfClass:[<Your View Controller Name> class]]) {
[self.navigationController popToViewController:controller animated:YES];
return;
}
}

Go like this to a particular view controller
[self.navigationController popToViewController:[[self.navigationController viewControllers]objectAtIndex:1] animated:YES];

Related

How to switch between view controllers and get rid of the previous one

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];

Generic way of Popping & Dismissing View Controllers

I am building an application in which, i have 3 ViewControllers.
Also i have created custom navigation controller.
A-ViewController -> This contains 2 buttons, 1st button is for opening B-ViewController & 2nd button is for C-ViewController.
From 1st button, I am using pushviewcontroller for B-ViewController, means B-ViewController is pushed from A-ViewController.
From 2nd button C-ViewController is presented using presentviewcontroller.
Now on pressing back button in both B & C ViewControllers, I have to use pop view controller in B-ViewController & dismiss in C-ViewController.
As currently i know the pages, but there should be a generic solution.
Is there any way to identify whether current navigation controller is pushed or popped.
As there are some pages which can be pushed or presented, but i dont want to set any bool variable. I need use the support from apple.
NSArray *arrViewControllers = [[AppDelegate sharedInstance].navigationController viewControllers];
NSLog(#"[arrViewControllers count] = %d",[arrViewControllers count]);
I am using the above code for fetching the list of view controllers in the stack.
But i am not able to identify whether it is pushed or presented.
Can anybody help me in this ?
You can check if your view controller exists in the navigation view controller's stack. Simply check it as
if([self.navigationController topViewController] == self){
//VC is the top most view controller
[self.navigationController popViewControllerAnimated:YES];
}else{
//You can put some checks here to be dead sure its a modally presented view controller
[self dismissViewControllerAnimated:YES completion:nil];
}
This is the code for Finding the navigation controller is presented or pushed from previous controller.
NSArray *arrViewControllers = [[AppDelegate sharedInstance].navigationController viewControllers];
UIViewController *viewController = [arrViewControllers lastObject];
if (viewController.presentedViewController)
{
[self dismissViewControllerAnimated:YES completion:nil];
}
else{
[self.navigationController popViewControllerAnimated:YES];
}

How to do circular and complex navigations?

In my program have 6 view controllers.(in storyboard)
Lets define 1,2,3,4,5,6.
1 is my main view.
I want to navigate like this(image bellow).Is it possible to do?
give me a idea to do this navigation.
Yes, u can implement this. This is a simple navigation in iOS using NavigationController.
you have six viewControllers 1, 2, 3, 4, 5, 6.
to do this:
First create a NavigationController and initialize it with ViewController 1 (ie a root View Controller).
Now your navigationController behaves like a stack which contains all ur pushed view controller. NavigationController is only push and pop ur view controllers.
So, every time when u want to navigation first check ur viewController is inside navigationController stack or not. If it is already in stack then pop to that controller, if not then push the same view controller.
for this use following:
In case ViewController3
-(void)popToSelectedViewController
{
NSArray *vc=[self.navigationController viewControllers];
ViewController3 *vc3=nil;
for (int i=0; i<[vc count]; i++)
{
UIViewController *tempVC=[vc objectAtIndex:i];
if([tempVC isKindOfClass:[ViewController3 class]])
{
vc=[vc objectAtIndex:i];
break;
}
}
if(vc3)
{
//If exists inside stack the pop
[self.navigationController popToViewController:vc3 animated:YES];
}
else
{
//If not exists inside stack push ViewController3
ViewController3 *vc3New= [[ViewController3 alloc]initWithNibName:#"ViewController3" bundle:nil];
[self.navigationController pushViewController:vc3New animated:YES];
[vc3New release];
}
}
For initializing ur ViewController1 with navigationController:
if using storyboard
Embed ur initialViewController(ie viewController3) with UINavigationController.
for this:
Step1: open storyboard, and select ur initialViewController(ie viewController3).
Step2: Go to Editor in menu -> Choose Embed In -> Select UINavigationController.
this creates a navigationcontroller and initializes with viewController3 as rootViewController.
if not using storyboard
make property of vc3 (ViewController3) and applicationNavigationController (UINavigationController) in .h
and in .m:
got method "application... didFinishedLaunching...." in appDelegate
and write:
self.vc3=[[ViewController3 alloc]initWithNibName:#"ViewController3" bundle:nil];
self.applicationNavigationController=[[UINavigationController alloc] initWithRootViewController:self.vc3];
self.window.rootViewController=self.applicationNavigationController;
[self.window makeKeyAndVisible];
First You create a navigation controller object
UINavigationController *navCtrl = [[UINavigationController alloc]initWithRootViewController:rootViewController];
self.window.rootViewController = navCtrl;
If you want to go to 1->2,1->3,1->6,etc, create an object for the next viewcontroller and push it to navigation stack
[self.navigationController pushViewController:second animated:YES];
You dont need to do any additional work to go back to the previous view controller. The default back button lets you go back.
If you need to return to the root view controller, then use this:
[self.navigationController popToRootViewControllerAnimated:YES];
if you want to return to any particular view controller, then use this
[self.navigationController popToViewController:viewController animated:YES];
Use UINavigationController.It is nor circular.It can be assumed as stacked approch.That is what navigation controller do
A must read for you

Need UISegmentControl with UINavigationController To Push ViewControllers

I have three UIViewControllers and one separate viewcontroller with UISegmentControl where i have to push 3 viewcontrollers using navigationControllers. I want all these views to appear below UISegmentControl when any segmentcontrol is selected. I tried push and pop logic, but couldn't get the result right. Below is the code for one controller-
-(IBAction)valueChanged:(id)sender{
segmentControl=(UISegmentedControl*)sender;
if (segmentControl.selectedSegmentIndex==1) {
firstView = [self.storyboard instantiateViewControllerWithIdentifier:#"FirstTopViewController"];
[self.navigationController pushViewController:firstView animated:YES];
[self.navigationController popViewControllerAnimated:NO];
self.navigationController.navigationItem.titleView=segmentControl;
NSLog(#"1");
}
}
Can anyone tell me what i'm doing wrong here?

Custom button push back

I have two views which use UINavigationController. I want the second view to "slide" with animation back to the first view when I tap on a custom button. (not the original in navigationbar)
Try something like this on that button action,
[self.navigationController popToViewController:aViewController animated:YES];
or
[self.navigationController popToViewController:[self.navigationController.viewControllers objectAtIndex:([self.navigationController.viewControllers count] - 2)] animated:YES];
Here aViewController represents the previous view controller. Similarly you can pop to any viewcontroller you want by using a similar code.
[self.navigationController popToRootViewControllerAnimated:YES]; will take you to the root view controller.

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