Here is my project:
It only crashes in iOS8.
I have 5 view controllers:rootViewController,A,B,C and D.Every view controller has a button that present another view controller except D. Evert time presenting a view controller, the Manager singleton object will add the presented view controller into an array. The last view controller D, which has a dismiss button, will use the array to dismiss view controller,and here's the code:
while ([Manager sharedManager].viewCont.count) {
UIViewController *viewController = [[Manager sharedManager].viewCont lastObject];
[viewController dismissViewControllerAnimated:NO completion:nil];
[self removeViewCon];
}
But I meet a crash,which shows:
I use some manage object because I want to manage the view controllers in some case.
My question is why this crash occurs when in "while" statement? Is it about runloop or iOS8 has some features like UIPresentationController that will not allow this case? And how to fix this?
Thanks in advance.
I just hit this also. It seemes the UIPresentationController crashes if it's presenting view disappears before it is done using it. One fix is to keep the view controller around a little bit longer.
Related
I got a very interesting problem here. My iPhone app has an UITabbarController as rootViewController in the AppDelegate.
If the app is opened the first time, it must be configured basically. For this purpose I create an UINavigationController and tell the tabbarController to present it modally:
firstRun = [[firstRunViewController alloc] init];
navCtrl = [[UINavigationController alloc] initWithRootViewController:firstRun];
[[self tabBarController] presentModalViewController:navCtrl animated:NO];
When the configuration is done, I'd like to get rid of the firstRunViewController. I'm using this technique very often, using -dismissModalViewControllerAnimated:.
But in this constellation this doesn't work. It doesn't matter from what controller I'm calling the dismiss.
I tried it via the tabbarController, the rootViewController, the currently active viewController, of cause self and several other controllers.
EVERY TIME I call -dismissModalViewControllerAnimated: I get this exception:
'UIViewControllerHierarchyInconsistency', reason: 'presentedViewController for controller is itself on dismiss for: <UINavigationController:…
Can anybody help? Thanks in advance, with kind regards, Julian
EDIT
In my AppDelegate I'm using a UITabbarController as rootViewController for the main window:
self.window.rootViewController = self.tabBarController;
[self.window makeKeyAndVisible];
Then I'm creating an UINavigationController and tell the UITabbarController to present the modalViewController:
UINavigationController *navCtrl = [[UINavigationController alloc] initWithRootViewController:firstRun];
[[self tabBarController] presentModalViewController:navCtrl animated:NO];
When I now call -dismissModalViewControllerAnimated: on the firstViewController I'm getting the error from above.
In my opinion you are abusing UITabbarController. This class, even though a subclass of UIViewController, does not really use much of the UIViewController infrastructure.
What you want is a slight extension of what you have now. Create a new UIViewController subclass in your appDelegate, and add it as the single object to an array, and set the tabBar's viewControllers to this array. Set your subclass' hidesBottomBarWhenPushed to YES so it hides the tab bar when it becomes visible.
Now your app will launch and your UIViewController subclass will become the frontmost view. You can make this view the one you wanted to present modally, or you can present that view from your subclass using some kind of animation. Oh, and if you use the launch view as the background image for your subclass, you can really make this a smooth transition - I do this now.
When your modal view is done, then you can instantiate whatever views you want to then display, and set the UITabBarController to use those views with tabBarController.viewControllers (or the animated version). Poof, you UIViewController will get replaces (and under ARC just disappear).
I don't have a chance to test my hypothesis, but I suspect that this issue could depend on the fact that you are presenting the modal view too early, whereby too early means before the main window has had the chance to set up the tab bar controller. So, I would suggest this changes:
create a method to instantiate your navigation controller:
- (void)initializeAndPresentNavigationController {
UINavigationController *navCtrl = [[UINavigationController alloc] initWithRootViewController:firstRun];
[[self tabBarController] presentModalViewController:navCtrl animated:NO];
}
instead of presenting the navigation controller directly from appDidFinishLaunching, call the above method asynchronously:
[self performSelector:#selector(initializeAndPresentNavigationController) withObject:nil afterDelay:0.0];
Here the trick of calling the method as I do in 2 is that the call to initializeAndPresentNavigationController will be simply pushed on the main loop, and executed after your app has had the possibility to build its initial UI.
Hope it works for you.
I finally found the answer myself!
I just couldn't see the wood for the trees! I'm quite happy right now! :)
I did really silly things: In the last viewController of the setup viewControllers I had to change the tabars viewControllers corresponding to whether the user is administrator or not. So I did:
appDelegate.tabBarController.viewControllers = [NSArray arrayWithObjects:appDelegate.readState,
appDelegate.navCtrl,
appDelegate.settings, nil];
You can see that I was adding the AppDelegate's "navCtrl" to the tabbar's viewControllers. So I was trying to dismiss a viewController I just added to the parentViewControllers (UITabbarController) sub-controllers.
Dismissing something I want to present just in the same moment is NOT advisable! :))
I've just created a storyboard with few table controllers and one view controller.
Everything works fine until my app push the view controller: it's shown completely black.
I can add map view, image view or whatever, or even nothing (a complete empty view controller), but it's always shown black.
I push it using the the navigation [self.navigationController pushViewController] code line.
This is not happening with table controllers, just with view controllers.
Any suggestion?
I'm using Xcode 4.3.2 4E2002.
Thanks in advance,
Samuel
Have you defined your storyboard correctly? This behavior could happen if you failed to properly initialize your storyboard and instantiate your controller from the storyboard. IE, you need to create a UIStoryboard object and need to instantiate your controller by calling
[storyboardObject instantiateViewControllerWithIdentifier: #"controllerName"]; ...See the thread here: http://mobile.tutsplus.com/tutorials/iphone/ios-5-sdk-storyboards
A UIViewController (View A) invokes another view controller (View B) by invoking it as a modal control.
[self presentModalViewController:ViewB animated:TRUE];
And View B exists by invoking:
[self dismissModalViewControllerAnimated:TRUE];
When this occurs everything looks right EXCEPT that View A's viewWillAppear and viewDidAppear does not get called (they are called during app init though). Weird thing is... i believe ive done this before, but im not sure what is going on now.
Is there anything obviously wrong that im doing?
Thanks!
* UPDATE *
I just now learned that this behavior only occurs with the UIModalTransitionStylePartialCurl transition type. For all other transition types the parent view-controller gets its viewDidAppear message just fine.
So now what am i suppose to do!?!
I just ran in to the same problem.
I solved it by adding a delegate and a delegate method.
So when Controller A opens Controller B as a modal view controller with a page curl i set the instance of controller b's.delegate to be controller a.
In controller B i add this:
-(void) viewWillDisappear:(BOOL)animated {
[super viewWillDisappear:animated];
if (delegate)
[delegate didCloseInfoViewController];
}
I have an issue .
I have code that reads in RSS feeds, its navigation based.
RssFunViewController - > thats the view for the table (list of feeds)
NewsDetailViewController - > thats shows more information about the news feed which was selected by user (in a new view).
But when i try to use it in a tab-based navigation project it doesnt work. I just get the table of RSS feeds, When i click an item i dont see the detailed view.
I think my issue is the connection with the tab controller and my classes.
For my 3rd navigation tab I set RssFunViewController as the class.
My question is how do i connect my RSSFunViewController and NewsDetailViewController so when the user clicks the item I see the detailed view.
Heres my current connections in my tab controller:
www.freeimagehosting.net/uploads/535e439c7f.jpg
Thanks everyone.
Maybe I have to disappoint you, but iPhone coding has a very steep learning curve past the drag&drop and connect the dots phase, where you actually have to understand things and make them work using code.
Although the information you give is very limited, here's a brief outline of how the table click action could be handled.
The table should have it's delegate and data source connected to the right class (may be, but does not have to be the same class).
The delegate class should contain a method
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
which will be called when a table entry is tapped. indexPath.row will then give the row number of the tapped entry.
In this method, you could present another view controller showing details, e.g. like:
NewsDetailViewController *ndvc = [[NewsDetailViewController alloc] autorelease];
ndvc.delegate = self;
[ndvc setFeedId:indexPath.row];
[ndvc initWithNibName:#"NewsDetailViewController" bundle:nil];
[self.navigationController pushViewController:ndvc animated:YES];
(assuming the NewsDetailViewController would have a setFeedId method etc.)
or you could have the NewsDetailViewController instantiated in your nib file so you could skip the alloc and initWithNibName steps, and put an "IBOutlet NewsDetailViewController *ndvc;" in the header file so you can connect them.
To remove the highlight from the tapped row, do
[tableView deselectRowAtIndexPath:indexPath animated:YES];
If you're working on a supplied project, you should be able to find lines like these already lying around. Good luck.
Whenever my app is rotated, only the viewController of which I've added his view as a subview to the mainwindow gets his interfaceOrientation property updated, the rest remains ignorant of the fact the device has been rotated.
Is it my responsibilty to notify other objects of the change, and if so, what's a nice way to do it?
I've looked into setting interfaceOrientation of my children-viewcontrollers but that's readonly.
Thanks in advance,
I found that calling
willRotateToInterfaceOrientation
and/or
didRotateFromInterfaceOrientation
of the view controller you are going to show worked for me. In my case I was using a Navigation Controller so it was easy to keep track of what was going to be shown to the user next. Below is some code from my project.
- (void)navigationController:(UINavigationController *)navigationController
didShowViewController:(UIViewController *)viewController
animated:(BOOL)animated {
[viewController willRotateToInterfaceOrientation:
[self interfaceOrientation] duration:0];
}