I am using a UISplitViewController on ARC.
I setup the controller in my AppDelegate, then make it the rootViewController. I have made sure to make it a property:
#property (strong, nonatomic) UISplitViewController *splitViewController;
Setting the root and detail using the viewControllers property works fine when first creating. And it works fine again when setting a second time, but I get a crash on the third time I try setting the viewControllers property.
Here is how I set those:
Screens *edit = [[Screens alloc] initWithStyle:UITableViewStyleGrouped];
UINavigationController *c = [[UINavigationController alloc] initWithRootViewController:edit];
if ([Utility isIpad]) {
Map *a = (Map *)[[MyAppDelegate instance].splitViewController.viewControllers objectAtIndex:0];
NSArray *viewControllers = [NSArray arrayWithObjects:a, c, nil];
UISplitViewController *splitView = [MyAppDelegate instance].splitViewController;
splitView.viewControllers = viewControllers;// <--- Crashes here
} else {
[self presentModalViewController:c animated:YES];
}//end
Why would it crash when I try to set the viewControllers property? It almost seems like it is released, but I know that the splitViewController is still there...
Could this be something to do with ARC?
Stacktrace:
I had the same error just now. In my case the problem was that I had originally set up the detail view controller to be a delegate of the UISplitViewController. Then I refactored to make the root view controller handle things, but I forgot to remove the connection from the .xib file.
So, when I set splitView.viewControllers the first time everything worked, but then my original detail controller would get released and the UISplitViewController was left with a bad pointer as delegate. The next time I set the viewControllers property, the UISplitViewController tried to call its delegate through the pointer and crashed.
You write that you set up the controller in your app delegate, so this may not be exactly the same problem you had. Still, double check to make sure the delegate property of the UISplitViewController is set correctly!
Related
I am setting up an iPad app that uses a SplitViewController. In my app delegate I have the following in didFinishLaunchingWithOptions:
UISplitViewController *splitViewController = (UISplitViewController *)self.window.rootViewController;
UINavigationController *leftNavController = [splitViewController.viewControllers objectAtIndex:0];
LeftViewController *leftViewController = (LeftViewController*)[leftNavController topViewController];
DetailViewController *detailViewController = [splitViewController.viewControllers objectAtIndex:1];
NSLog(#"Detail View Ctrl >> %#", [detailViewController class]);
When I run the app, the NSLog statement returns "UINavigationController" when DetailViewController is actually a subclass of UIViewController. However, in XCode, code completion shows all the methods that are implemented in the DetailViewController subclass. Any ideas? Thanks!
I think your DetailViewController is actually embedded inside a UINavigationController, and your fourth line is in error. Take a look instead at the topViewController for the second view controller inside your split view controller, much like you do for the LeftViewController.
The reason Xcode is continuing to suggest completion for DetailViewController methods is because you've given it that type. Code completion doesn't rely on runtime behavior (how could it?) – instead, it relies on static analysis of the code that you type. If you tell Xcode that something is a DetailViewController, it'll believe you and autocomplete based on that information.
VC1 = NewGameViewController
VC2 = GameViewController
NewGameViewController.m
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if( [segue.identifier isEqualToString:#"newGameSegue"]) {
GameViewController *gameVC = (GameViewController *)segue.destinationViewController;
NSArray *array = [self nameArrayForTextFieldArray:self.namePicker.textFieldArray withColon:YES];
gameVC.nameArray = [[NSArray alloc] initWithArray:array];
}
-(NSArray *)nameArrayForTextFieldArray:(NSArray *)array withColon:(BOOL *)bool
basically returns an nsarray of strings given an nsarray of textfields. withcolon is a bool of whether or not you want the strings to have a colon appended to the end.
when i debug my code, the _nameArray ivar in gameVC still reads nil after every line here is called...can anyone help me out here??
The prepareForSegue method is invoked by UIKit when a segue from one screen to another is about to be performed. It allows us to give data to the new view controller before it will be displayed. Usually you’ll do that by setting its properties.
The new view controller can be found in segue.destinationViewController. If GameViewController embed the navigation controller, the new view controller will not be GameViewController but the navigation controller that embeds it.
To get the GameViewController object, we can look at the navigation controller’s topViewController property. This property refers to the screen that is currently active inside the navigation controller.
To send an object to the new view controller you can use this solution using performSegueWithIdentifier:
For example, if we want to perform a segue pressing a UIButton we can do this:
In the MyViewController.h we create a IBAction (connected to UIButton), dragging the button from storyboard to code:
- (IBAction)sendData:(id)sender;
In MyViewController.m we implement the method:
- (IBAction)sendData:(id)sender
{
NSArray *array = [self nameArrayForTextFieldArray:self.namePicker.textFieldArray withColon:YES];
[self performSegueWithIdentifier:#"newGameSegue" sender:array];
}
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([segue.identifier isEqualToString:#"newGameSegue"]) {
UINavigationController *navigationController = segue.destinationViewController;
GameViewController *controller = (GameViewController *)navigationController.topViewController;
controller.nameArray = sender;
}
}
Is GameViewController embedded in a navigation controller? In that case, your destinationViewController property is of type UINavigationController, not GameViewController. You can get to GameViewController by calling [segue.destinationViewController.viewControllers lastObject].
I'm assuming that you've done a NSLog (or examine it in the debugger) of array immediately before setting gameVC.nameArray. You really want to make sure it's being set the way you think it is. It's amazing how many times I've spent debugging something like this only to realize the problem was in my equivalent to nameArrayForTextFieldArray. Or a typo in the name of the segue identifier. Or random things like that.
Assuming that's ok, then a couple of things are possible:
How is your nameArray property defined in GameViewController? If it's not a strong reference (or a copy), then when your array falls out of scope, it will be deallocated. I think this would manifest itself slightly differently, but it's worth confirming.
Also, I've seen situations where a controller like GameViewController might have some confusion between various ivars and properties (which is why I never define ivars for my properties ... I let #synthesize do that).
I assume you're not using a custom setter for nameArray. I just want to make sure. If so, though, please share that, too.
Bottom line, can you show us all references to nameArray in your #interface of GameViewController as well as in its #synthesize statement?
Since appDelegate does not have a view, just window, its hard to figure out how to load a view from it. My problem has for long been that when didReceiveLocalNotification fires i cant load a new view with that event. I have been working around it til the point that i must do something about it. When i tries to addSubview, xcode gives me the error:
Receiver tupe 'UIWindow' for instance messages does not declare a method with selector 'addSubView'
for this: (at [self.window addSubView:view];)
screwLightBulbViewController *view = [screwLightBulbViewController newMyView];
[self.window addSubView:view];
I understand that the appDelegate file does'nt have a addSubview but i want to switch to a particular view when it fires.
I have tried many other ways, like calling a function in screwLightBulbViewController and make a view from that. My function in the viewController now looks like this:
+(id)newMyView
{
UINib *nib = [UINib nibWithNibName:#"MyView" bundle:nil];
NSArray *nibArray = [nib instantiateWithOwner:self options:nil];
screwLightBulbViewController *me = [nibArray objectAtIndex: 0];
return me;
}
any help in any way would be realy appreciated and thanks for you time. :)
It's addSubview not addSubView:. UIWindow is a subclass of UIView.
Adding a view directly as a subview to the window is not usually recommended, so instead you should try and add the view as a subview to the top controller view. If you can spare some time you should look over the view programming guide and view controller programming guide, it will be useful in the future.
Any help is appreciated ! It's several days I'm fighting w/o results.
The scenario:
I and iPad application have a SplitViewController that shows 2 controllersViews (Root on the left e Detail on the right)
The Root allows a recursive navigation (tree that could be several drilldown levels) and I'm calling every time the same controller class (UITableView) pushing always in the controller stack). When the user taps a cell (left side), the detail view (right side) shows the information.
Keep in mind that the detail view controller is not always the same class: it means that I'm allocating (and releasing) programmatically several detailView controllers according the kind of information I have to display.
Here the fragment:
UIViewController <ItemGenericViewController> *newDetailViewController = [[NSClassFromString(cntrClass) alloc] initWithNibName:cntrXib bundle:nil];
//the detailViewController has been defined in the head section as ItemGenericViewController
//each detailViewController is a subclass of ItemGenericViewController
detailViewController = newDetailViewController;
UINavigationController *nav = [[UINavigationController alloc] initWithRootViewController:detailViewController];
// Update the split view controller's view controllers array.
NSArray *viewControllers = [[NSArray alloc] initWithObjects:self.navigationController, nav, nil];
self.splitViewController.viewControllers = viewControllers;
[nav release];
[viewControllers release];
[detailViewController release];
Everything is working fine until a memory warning arises.
From that moment if I try to display a new detailViewcontroller the "connection" in the SplitViewController, between the RootController and the detailController, seems vanished. The result is: nothing appear on the right part of the splitController.
In the mean time if I navigate to parent level in the root controller the situation still failing.
For your information each time I push in the stack a new RootController instance (left column) I'm releasing the same controller (to save memory as usual) and I suspect, after receiving the memory warning, iOS is trying to free itself memory and my "history" disappear and the related connection, throught the split controller, too.
Is a nightmare ;-)
Do you have any suggestion ?
Thanks
Dario
I had a similar problem to you (maybe even worse - 16 combinations of possible view switches)... But I believe i have solved it right now.
So, i believe you have used Apple's example for view switching (I have, with modifications), and if you have so, problem is that "root" splitViewController (from MainWindow.xib) get's "niled" as default behavior when memory warning. And even if you add new array of view controllers to it, it will not cause any change (and even worse, it will not show any sign of warning). And solution is to check is it nil, and if is, to reinitialize it.
here is the code, using example from above:
UIViewController <ItemGenericViewController> *newDetailViewController = [[NSClassFromString(cntrClass) alloc] initWithNibName:cntrXib bundle:nil];
//the detailViewController has been defined in the head section as ItemGenericViewController
//each detailViewController is a subclass of ItemGenericViewController
detailViewController = newDetailViewController;
UINavigationController *nav = [[UINavigationController alloc] initWithRootViewController:detailViewController];
// Update the split view controller's view controllers array.
NSArray *viewControllers = [[NSArray alloc] initWithObjects:self.navigationController, nav, nil];
/**** Milos Edit ****/
if (self.splitViewController == nil) {
// I'm keeping reference in app delegate, but any way to reinitialize splitViewController is OK
self.splitViewController = delegate.splitViewController;
}
/**** end of edit ****/
self.splitViewController.viewControllers = viewControllers;
[nav release];
[viewControllers release];
[detailViewController release];
Hope it will be helpful.
Cheers
Milos
I was under the impression that adding a subview to a view goes like this:
UITableViewController *sitesel = [[UITableViewController alloc] initWithStyle:UITableViewStyleGrouped];
sitesel.view.frame = CGRectMake(0,0,100,100);
[self.left addSubview:sitesel.view];
[sitesel release];
But it seems I should not release the sitesel (the controller)?
So should I release the view or what, I had this retain stuff nailed a while ago, but it's slipped. (And to use a TableView, you have to subclass UITableViewController right?)
(self.left is a subview of self.view, added in a nib)
addSubview does retain the view, that's not the problem. Your issue is that the controller for the view goes away a little later.
You shouldn't release the view, because that's none of your business. You didn't create it, you didn't touch it. Leave it alone.
In order to keep things working, it needs to stay connected to a valid controller. Hence, you must not release the controller, but keep it around. Add a property like #property(retain) UITableViewController *siteController; and then do self.siteController = sitesel; before you release the controller. This way everything stays in memory.
PS: For cleanness, you should probably change the view in the accessor for sitesel. Just to make sure it always comes and goes along the controller. Your method would then get even shorter, just setting the controller.
ADDED: That setter could look like that, requiring you to set only the controller and the view being updated transparently:
- (void)setSiteselController:(UITableViewController *)ctrl {
if (_sitesel)
[_sitesel.view removeFromSuperview];
[_sitesel autorelease];
_sitesel = [ctrl retain];
if (_sitesel) {
_sitesel.view.frame = CGRectMake(0,0,100,100);
[self.left addSubview: _sitesel.view];
}
}
Your original code will then shrink to this much cleaner version:
UITableViewController *sitesel = [[UITableViewController alloc] initWithStyle: UITableViewStyleGrouped];
self.siteselController = sitesel;
[sitesel release];
PPS: You don need an controller for a UITableView to work. It's just much simpler!