I'm developing a single view iOS 5.0+ app and I'm going to navigate throw my ViewControllers this way:
SearchViewController* search =
[[SearchViewController alloc] initWithNibName:#"SearchViewController"
bundle:nil];
[self presentViewController:search
animated:NO
completion:nil];
My question is, if I'm opening SearchViewController from HomeViewController, is HomeViewController dismissed after SearchViewController is shown?
I have a lot of UIViewControllers and I don't know if all of them will be on memory while user is navigating between them.
If You want to Present Only one Viewcontroller you can try like,
SearchViewController* search =
[[SearchViewController alloc] initWithNibName:#"SearchViewController"
bundle:nil];
[self dismissViewControllerAnimated:NO completion:^{
[self presentViewController:search
animated:NO
completion:nil];
}];
When you present a ViewController from another ViewController, they never get released from memory. To release them from memory you need to explicitly dismiss them.
The method presentViewController:animated:completion: sets the
presentedViewController property to the specified view controller,
resizes that view controller’s view and then adds the view to the view
hierarchy.
So you see you are getting a stack of ViewControllers and adding a View on top of another.
Related
I have the whole app embedded in UINavigationController. Now there is the Home Screen that has several modules for user to choose. Now, when the user clicks on the module it is NAVIGATED and if user desires to choose some another module from any other modules available, there is a button in navigation bar, which PRESENTS the HomeViewController modally on top of the current module and then user can choose any module from there which will NOT BE PRESENTED instead they will NAVIGATE.
Now what I have done is made a delegate called navigate on HomeViewController and will be override by viewcontrollers of each module and it will take the reference of the new ViewController with it. Then when this method is called I have first dismissViewController the HomeViewController and then navigated to the new ViewController that I have the reference.
Now, what the real issue is that SOMETIMES there is a jerk when navigating from one module to other and sometime it works fine. That why I am not able to debug also. The jerk is that when a module is clicked from HomeViewController, the home screen disappears and the appears again and then it actually navigates.
The code for navigating to a module from HomeViewController is
RadiusSearchViewController *rad = [self.storyboard instantiateViewControllerWithIdentifier:#"RadiusSearchViewController"];
[self.delegate navigate:rad];
This navigation overrided method in all modules is
-(void)navigate:(UIViewController*)uiViewController{
NSLog(#"inside navigate method");
[self.presentedViewController dismissViewControllerAnimated:YES completion:nil];
[self.navigationController pushViewController:uiViewController animated:YES];
}
I assure you that it is coming in this method.
Now the code that presents the HomeViewController modally is
ViewController *vc = [self.storyboard instantiateViewControllerWithIdentifier:#"HomeVC"];
vc.view.backgroundColor = [[UIColor whiteColor]colorWithAlphaComponent:0];
vc.delegate = self;
vc.providesPresentationContextTransitionStyle = YES;
vc.definesPresentationContext = YES;
vc.modalPresentationStyle = UIModalPresentationOverCurrentContext;
vc.fromOutside = true;
NSLog(#"Presneting...");
[self presentViewController:vc animated:NO completion:nil];
The reason for PRESENTING and NOT NAVIGATING the HomeViewController is that it comes on the top of the current module in transparent form which is necessary.
REMEMBER: It happens sometimes not all of the time. Like you can say half of the times.
[self.presentedViewController dismissViewControllerAnimated:YES completion:nil];
[self.navigationController pushViewController:uiViewController animated:YES];
this should be changed to...
[self.presentedViewController dismissViewControllerAnimated:YES
completion:^{
[self.navigationController pushViewController:uiViewController animated:YES];
}];
this will make sure navigation view controller will be called after dismiss is done. check and see if it solves your problem.
This is the goal :
I have a navigation controller (NC1), that is presenting modally some view controller (VC). When I do some action in that view controller, I need to (invisibly for the user) dismiss VC, dismiss NC1, then present another navigation controller (NC2) and present the same view controller VC.
In iOS 7.0, 7.1 this is working well via this (slightly adjusted) code:
[controller dismissViewControllerAnimated:NO completion:nil]; //dismiss VC
[self.presentedViewController dismissViewControllerAnimated:NO completion:nil]; //dismiss NC1
SomeViewController * someViewController = [[SomeViewController alloc] init]; // root vc for NC2
NavigationController * navigationController = [[NavigationController alloc] initWithRootViewController:someViewController]; //NC2
SomeViewController2 * someViewController2 = [[SomeViewController2 alloc] init];
[navigationController presentSomehow:someViewController2 animated:NO completion:nil]; //another pushed to NC2
[someViewController2 presentViewController:controller animated:NO completion:nil]; //present VC again
but in iOS 8 (Xcode 6.0) it seems that even after dismissing, VC remains active and the app crashes at the last line with:
Application tried to present modally an active controller ...
And of course if I move the code to completion blocks the changes are visible to user (and ugly).
Is there a way to check or force the VC to leave the active state, or some other way to simulate the iOS 7 behavior?
Thanks for answers!
I have an ipad app.
I am trying to open view 2 (kind of push view) full with entire screen. how normally do with push view or UIModalPresentationFullScreen. but my base view which is view 1 is also modal view.
so i was trying to open view 2 when view 1 get dismiss…
- (void) handleNewButton :(int)id
{
[self dismissViewControllerAnimated:YES
completion:^{
NewViewController *View2 = [NewViewController alloc] init];
View2.modalPresentationStyle = UIModalPresentationFullScreen;
View2.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
[self presentViewController: View2 animated:YES completion:nil];
}];
}
but my view 2 is not opening. i know i can not do push view. But is there any way to achieve it?.
When you do this dismissViewControllerAnimated the UIViewController (self in this case) is gone, in the sense that he is not on the screen anymore, if it has been released or not, that's another story. The reason for you to not be able to show the View2 (very poor name, it should at least ViewController2) is because you are trying to show it from a UIViewController that is not on the screen anymore.
So, what can you do?
The current self in the context of the handleNewButton method, in theory was presented by another UIViewController, that's from where you want to present your View2.
Probably the quickest way of implementing of what I said, would probably be with a notification described here. Although I would do it with a block, so when the self would be created, I would pass a dismissiCompletionBlock that would be called when that UIViewController was dismissed.
try to allocate NewViewController with nib name if you are not using storyboard,
[self dismissViewControllerAnimated:YES
completion:^{
NewViewController *n=[[NewViewController alloc]initWithNibName:#"NewViewController" bundle:nil];
View2.modalPresentationStyle = UIModalPresentationFullScreen;
View2.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
[self presentViewController: View2 animated:YES completion:nil];
}];
or if you are using storyboard get NewViewController using identifier.
In my app i present a UINavigationController modally with a UIViewController as its rootViewController. I do it in form style. I added a second UIViewController which is also in form style and i can push to it fine. However when i perform a popViewController action after the second UIViewcontroller gets popped onto the first, the whole modally presented UIViewController gets dismissed. However i don't perform any dismissing and the dismissing function doesn't get triggered by accident either.
Any ideas why it's happening?
Sincerely,
Zoli
EDIT:
That's how i'm presenting the modal viewcontrollers with a navcontroller:
if(!welcomeScreenAlreadyPresented) {
welcomeScreenViewController = [[WAWelcomeViewController alloc]init];
}
welcomeScreenNavController = [[UINavigationController alloc]initWithRootViewController:welcomeScreenViewController];
[welcomeScreenNavController setModalTransitionStyle: UIModalTransitionStyleCrossDissolve];
[welcomeScreenNavController setModalPresentationStyle:UIModalPresentationFormSheet];
[welcomeScreenNavController setNavigationBarHidden:YES animated:NO];
[self.navigationController presentViewController:welcomeScreenNavController animated:YES completion:nil];
That's how i'm navigation in WAWelcomeViewController.m
registerViewController = [[WARegisterViewController alloc]init];
[self.navigationController pushViewController:registerViewController animated:YES];
And in WARegisterViewController.m that's how i pop back
[self.navigationController popViewControllerAnimated:YES];
What you need to do is put the viewController you want to push inside another UINavigationController.
registerViewController = [[WARegisterViewController alloc]init];
UINavigationController *modalNavigationController = [[UINavigationController alloc] initWithRootViewController:registerViewController]; // autorelease if you are not using ARC
[self presentViewController:navController animated:YES completion:^{}];
You might want to add the modalNavigationController as a property to later call popViewControllerAnimated: on it.
When the user clicks a button it presents a new tab bar view controller with two view controllers. Here's how I do that
ACLevelDownloadController *dvc = [[ACLevelDownloadController alloc] initWithNibName:#"ACLevelDownloadController" bundle:[NSBundle mainBundle]];
ACInstalledLevelsController *ivc = [[ACInstalledLevelsController alloc] initWithNibName:#"ACInstalledLevelsController" bundle:[NSBundle mainBundle]];
UITabBarController *control = [[UITabBarController alloc] init];
control.viewControllers = #[dvc, ivc];
dvc.tabBarItem = [[UITabBarItem alloc] initWithTabBarSystemItem:UITabBarSystemItemFeatured tag:0];
ivc.tabBarItem = [[UITabBarItem alloc] initWithTabBarSystemItem:UITabBarSystemItemDownloads tag:1];
[self presentViewController:control animated:YES completion:nil];
this works fine. I dismiss that view controller with a dismiss method in both the ACLevelDownloadController and ACInstalledLevelsController. That also works fine. What's strange is that the memory usage goes up when I present the view controller
but it never goes back down. If I present it again, it goes up even more
I'm using ARC. Why is the memory that the view controllers use not being released after they are dismissed?
EDIT
The way they are dismissed is both ACLevelDownloadController and ACInstalledLevelsController have IBActions hooked up that call this method when they are clicked
- (void)dismiss:(id)sender{
[self dismissViewControllerAnimated:YES completion:nil];
}
What we can observe from the memory usage graph is that the tabViewController is not being dismissed properly and it builds up in the stack. While dismissing you have to allow the viewController which presented the tabViewController to dismiss it. It is its responsibility to dismiss. Also keep weak references for Outlets and assign any strong references to nil** in viewWillDisapper: . You can present a viewController modally as a temporary interruption to obtain important information from the user. If its not the case here, you can remove presenting modally. Check this link. Hope this helps :)