How to jump to a specific view? - iphone

I have 3 views (xib'd) the third view opens a modal view (also xib'd).
My goal is to dispose the modal view and jump on the view #1.
I used the following code but it does nothing.
self.statusView = [[StatusViewController alloc] initWithNibName:#"StatusViewController" bundle:nil];
[self.navigationController popToViewController:self.statusView animated:YES];
[self.navigationController popToViewController:
I also tried the following, same result.
[self.navigationController.viewControllers objectAtIndex:0] animated:YES];
I'm going crazy...
statusView has an accessor regularly synthetized and it represents the view that I want to jump to.

It is not entirely clear how your views are set up with respect to each other, based on what you've said so far.
I'm guessing you have a navigation controller, and 3 view controllers that are displayed on the navigation stack.
If that's the case, and you want to pop back by two screens at once (from #3 to #1, skipping #2), then you need a pointer to the view controller for #1 (not the view itself). It looks as if the first popViewController: method call in your question is sending in a view.
Sample code to pop to the first view controller:
UINavigationController* navController = self.navigationController;
UIViewController* controller = [navController.viewControllers objectAtIndex:0];
[navController popToViewController:controller animated:YES];
If you've tried this, and it doesn't work, a few things might be going wrong:
Maybe self.navigationController isn't actually the right object.
Maybe the view you expect isn't actually view #0 on the navigation stack.
Maybe the navigation controller you're working with isn't currently visible.
Here are some further steps you can take to test these hypotheses:
When you first allocate the navigation controller you want to work with, call NSLog(#"Nav controller is at %p", navController); and in this code add a call to NSLog(#"Now my navController is at %p", navController); and check that the addresses match.
If the nav controller is the right one, print out the current navigation stack; something like this (which assumes each view controller has a different class name):
for (UIViewController* viewController in navController.viewControllers) {
NSLog(#"%s", class_getName([viewController class]));
}
Do something visual to the navigation controller you think is visible to make sure it actually is. For example [navController.visibleViewController.view addSubview:aColorFulView]; where aColorFulView is some visually obvious UIView.

-popToViewController lets you pop controllers OFF the stack. What you want to do is push new viewControllers ONTO the stack, so use:
[self.navigationController pushViewController: self.statusView animated: YES];

Related

Go to first view controller in app

I need to go to the first view in my app. I have a few views pushed onto the stack then a modal navigation controller and more views pushed onto that.
The problem I'm having is that using [[self navigationController] popToRootViewControllerAnimated:YES]; only goes back to the first view in the modal stack.
And I can't get [[self navigationController] popToViewController:.. to work because the true first view controller isn't accesible with [[self navigationController] viewControllers].
Any ideas on how to accomplish this? Thanks.
Do this:
[[self navigationController] dismissModalViewControllerAnimated:YES];
That will get you back to the VC that modally presented the navigation controller. Getting farther back after that depend on how you pushed those "few views" before the navigation controller.
Edit - explanation to get to the deepest root...
It sounds like those "few views" are on another, underlying navigation controller's stack. This can be a little tricky, because the clean way to get farther back in that stack is to have that underlying navigation controller pop to it's own root. But how can it know that the modal VC on top of it is done?
Let's call the view controller that did the modal presentation of second navigation controller VC_a. It's a modally presented navigation controller whose topmost VC is VC_b. How can VC_a know to pop to it's navigation root when VC_b modally dismisses itself?
The good answer (usually) is that VC_b decided to dismiss itself for a reason - some condition in your app/model changed to make it decide to be done.
We want VC_a to detect this condition, too. When VC_b gets dismissed, and VC_a gets a viewWillAppear message because it's about to be uncovered:
// VC_a.m
- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
if (/* some app condition that's true when VC_b is done */) {
// I must be appearing because VC_b is done, and I'm being uncovered
// That means I'm done, too. So pop...
[self.navigationController popToRootViewControllerAnimated:NO];
} else {
// I must be appearing for the normal reason, because I was just pushed onto the stack
}
}
You need to do it by using the delegation pattern. Specifically, by creating a protocol that implements the delegate's respondsToSelector method.
See this post for complete details. It should be almost exactly what you are looking for. I had to do something similar, except I only needed to pop one view off the navigation stack instead of using popToRootViewControllerAnimated:.
For iOS6...
[self.view.window.rootViewController dismissViewControllerAnimated:YES completion:nil];
In AppDelegate.m class create method with bellow flow...
-(void)MethodName{//your method name
YourViewController *objViewController = [[[YourViewController alloc] initWithNibName:#"YourViewController" bundle:nil] autorelease]; ///define your viewcontroller name like "FirstViewController"
UINavigationController *yourNavigationController = [[[UINavigationController alloc] initWithRootViewController:objViewController] autorelease];
self.window.rootViewController = yourNavigationController;
}
When you want redirect on firstview just call this method from appdelegate object....

I can came back to first navigation control page with a button?

-(IBAction) btnReturn:(id) sender{
firstView * firstview =[[firstView alloc]initWithNibName:#"firstView" bundle:nil];
[self.view pushViewController:firstview animated:NO];
}
with the previsly code I see the first view but the navigation control increment. I wold came bak as was the navigation starting point. Any help?
pushViewController:animated: will add to the navigation stack; you want popViewControllerAnimated: to go back one view in the stack.
If you want to return to the very first (root) view controller, you want popToRootViewControllerAnimated:.
See: https://developer.apple.com/library/ios/#documentation/UIKit/Reference/UINavigationController_Class/Reference/Reference.html
In your above code you are pushing a controller on self.view (firstView, I am considering it as controller as you are creating it using initWithNibName: method, but you should you proper naming conventions to avoid confusions.) But view do not have any such method pushViewController:. Instead you sould use if you really have self (the controller in which you are using this IBAction) in navigation stack.
[self.navigationController pushViewController:firstview animated:NO];
To pop controller from navigation stack, follow what #gregheo suggested.
Try using popViewControllerAnimated instead:
- (IBAction)btnReturn:(id)sender
{
[self.navigationController popViewControllerAnimated:NO]; // Or Yes if you would like to have an animation.
}

pushViewController only works with animated:YES

I have found a strange behaviour when trying to push a viewcontroller onto the stack. The following works fine:
[self.navigationController pushViewController:myViewController animated:YES];
but if I change it to animated:NO it no longer works, doesn't seem to push at all. I was performing this in a viewWillAppear but I have also tried it in viewDidAppear but with no luck.
Any ideas what could be causing this?
Thanks
The problem is most probably not the call itself, but the placement of the call. Try putting the same action on a UIButton and it should 100% work. I've noticed that putting view controller manipulation routines like presentModal... and pushViewController... don't sometimes work in the viewWill* viewDid* methods. Or try making the calls from those functions with a performSelector:withObject:afterDelay after a short delay and see if that works.
Edit: there are a couple of ways of doing what you want to do. You can directly modify the navigation stack of a navigation controller, so when you are in view N+1, you can replace view N on the stack (by building a new navigation stack array and setting it in to the navigation controller), then pop, and you'll get the effect of "popping back to a different view controller". You can also issue multiple pops and pushes from the view controller you want to leave, but you have to be careful:
// pop back 2 controllers on the stack to the setup screen
//
// locally store the navigation controller since
// self.navigationController will be nil once we are popped
//
UINavigationController *navController = self.navigationController;
// retain ourselves so that the controller will still exist once it's popped off
//
[[self retain] autorelease];
// Pop back 2 controllers to the setup screen
//
[navController popViewControllerAnimated:NO];
[navController popViewControllerAnimated:YES];

Navigation controller crashing on second time

I am using one navigation controller in my application. I am having one main view (with main view controller) and few options views. Options views are viewed by navigation controller when a button clicked on main view's toolbar.
Everything works as expected for first time. When I came back to main view from navigation controller and tries again to go to option view (i.e. navigation controller) my application crashes.
Following is my code,
//Jump to navigation controller from main view controller
optionsViewController *optionsView = [[optionsViewController alloc] initWithNibName:#"optionsView" bundle:nil];
navControllerSettings = [[UINavigationController alloc] initWithRootViewController:(UIViewController *) optionsView];
[self presentModalViewController:self.navControllerSettings animated:YES];
//Code to go back to main view from navigation controller
[self.navigationController dismissModalViewControllerAnimated:YES];
What is correct mechanism to handle navigation controller? Do I need to release/dealloc the navigation controller or options view?
Sample code will help better.
Your navigation controller only gets set up once, then you push and pop other views from its stack.
UINavigationController *navController = [[UINavigationController alloc] init];
UIViewController *yourMainViewController = [[yourMainViewControllerClass alloc] init];
// when you are ready to go to your options view
optionsViewController *optionsView = [[optionsViewController alloc] initWithNibName:#"optionsView" bundle:nil];
[navController pushViewController:optionsViewController animated:YES];
// the back button and the pop from the stack when it is hit is handled auto-magically for you
Thanks for the reply.
But my application architecture is, I am having one main view on which I display few things and having toolbar. Toolbar contains one button, after clicked on that this navigation controller gets created and displayed on the screen.
using back button I came on the main view. But then after I could not go on the navigation again as it is crashing while executing following line
[self presentModalViewController:self.navControllerSettings animated:YES];
What might be the problem here?
Vishal N
I had a similar problem to this with it crashing in presentModalViewController: on second attempt. The problem was caused by calling [self becomeFirstResponder] in viewDidAppear: inside the first UIViewController that I presented, but I failed to call [self resignFirstResponder] in viewWillDisappear:.

Is parentViewController always a Navigation controller?

I was kind of scratching my head at this a week ago, and now with a little bit more Cocoa experience under my belt I feel like I have an inkling as to what might be going on.
I'm making an application that is driven by a UINavigationController. In the AppDelegate, I create an instance of this class, using "page 1" as the Root View Controller.
UINavigationController *aNavigationController = [[UINavigationController alloc]
initWithRootViewController:page1ViewController];
Now here's where I'm having the problem. From "page 1" I'd like to use a modal view controller that slides over the interface and then disappears once the user has made an edit. I do that using code like this, inside of Page1ViewController:
[self presentModalViewController:myModalViewController animated:YES];
When the Modal View Controller is gone, I want a value on "Page 1" to change based on what the user entered in the Modal View Controller. So, I wrote some code like this, which resides in the Modal View Controller:
[self.parentViewController dismissModalViewControllerAnimated:YES];
[self.parentViewController doSomethingPleaseWithSomeData:someData];
The update to page 1 wasn't happening, and it took me a long time to realize that the "doSomethingPleaseWithSomeData" message was not being sent to Page1ViewController, but the Navigation Controller.
Is this always to be expected when using Navigation Controllers? Did I perhaps configure something improperly? Is there an easy way to get at the View Controller that I want (in this case, Page1ViewController).
I would recommend using the delegation pattern to solve your problem. Create a property
#property (nonatomic, assign) id <MyModalViewDelegate> delegate;
And a corresponding protocol
#protocol MyModalViewDelegate
#optional
- (void)myModalViewControllerDidFinish:(MyModalViewController *)aModalViewController;
#end
When the user finishes with your view (e.g. taps the save button), send this message:
if ([self.delegate respondsToSelector:#selector(myModalViewControllerDidFinish:)])
[self.delegate myModalViewControllerDidFinish:self];
Now, set the delegate to the view controller that should manage the whole thing, and it will be notified when the view controller is finished. Note that you'll need your view controller to dismiss the modal view controller. But, logically, that makes sense, since it was the object that presented the modal view controller in the first place.
This is how Apple solves this problem in, for example, the UIImagePickerController and UIPersonPickerController.
There are a couple of ways you can handle this. The simplest is probably just to add a UIViewController property into myModalViewController and set it to page1Controller before you present it:
myModalViewController.logicalParent = self; //page1Controller
[self presentModalViewController:myModalViewController animated:YES];
Just make sure you add the appropriate instance variable #property, and #synthesize for logicalParent to myModalViewController, then you will have a way to communicate data back to the ViewController that triggered the modal dialog. This is also for passing data back and forth between different levels of navigation before you push and pop them on the stack.
The one important thing to worry about when doing this is that it is easy to get retain loops if you are not careful. Depending on exactly how you structure this you might need to use assign properties.
I just ran into this same problem. It definitely seems that if you put a UIViewController embedded in a NavigationController, then when, from that UIViewController you present another UIViewController modally, the presentee thinks that the presenter is the NavigationController. In other words, parentViewController is incorrect.
I bet this is a bug: either that, or the documentation seems incomplete. I will inquire.
Just ran into the same problem. I believe this is a bug. My scenario is the following:
A navigation hierarchy with A, B and C view controllers in this order. On C there's a button that would open a modal view controller called D. Once D is presented the navigation controller drops C from its hierarchy which is a terrible behavior. Once D gets dismissed, the navigation controller instantiates a new C type view controller and pushes it into its hierarchy to recover the original one. Terrible. My solution is hacking the navigation hierarchy this way (a very bad solution but works well. with a 2 dimension array you could implement stacking modals):
- (void)presentModalViewController:(UIViewController *)c {
[self.navigationHierarchy removeAllObjects];
[self.navigationHierarchy addObjectsFromArray:[navigation viewControllers]];
[navigation setViewControllers:[NSArray array] animated:YES];
[navigation presentModalViewController:c animated:YES];
}
- (void)dismissModalViewController {
[navigation dismissModalViewControllerAnimated:YES];
[navigation setViewControllers:[NSArray arrayWithArray:self.navigationHierarchy] animated:YES];
}
These two methods are defined where I maintain the main navigation hiererchy: the app delegate. navigation and navigationhierarchy are defined this way:
NSMutableArray *navigationHierarchy;
UINavigationController *navigation;