ios: Navigation to another screen using modalTransitionsytle attribute, crashes the app

Question

I have Navigation interface which I use to pop to setting screen everytime uses presses settings button.

@interface Navigation : UINavigationController
{
}
-(void)popToMainMenuAnimated:(BOOL)animated;

//.m file
-(void)popToMainMenuAnimated:(BOOL)animated
{
    UIViewController *element;
    for(element in self.viewControllers)
    {
        if([element isKindOfClass:[MainSettingClass class]]){
          self.modalTransitionStyle = UIModalTransitionStylePartialCurl;
          [self presentModalViewController:element animated:YES]
        }
     }
}

App is crashing with below Exception.

* Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Application tried to present modally an active controller .' * First throw call stack:

NOTE: This not root screen but 3rd sceen of my application.

Kjuly Kjuly · Accepted Answer · 2011-12-09T11:33:15

Base on the debug log you gave I got a reason by searching:
MainSettingClass instance that you pushed before can neither be repushed to the array on navigationController again, nor be presented modally. You should create a new MainSettingClass instance and present it, just like the second code snippet.

HERE is a relate question that mentioned Application tried to present modally an active controller. :)

-(void)popToMainMenuAnimated:(BOOL)animated
{
    UIViewController *element;
    for(element in self.viewControllers) {
        if([element isKindOfClass:[MainSettingClass class]]) {
            self.modalTransitionStyle = UIModalTransitionStylePartialCurl;
            [self presentModalViewController:element animated:YES];
            break;
        }
    }
}

But why not load the Main Menu instead of pop?

-(void)loadMainMenuAnimated:(BOOL)animated
{
    MainSettingClass * mainMenuViewController = [[[MainSettingClass alloc] init] autoreleased];
    [mainMenuViewController.view setFrame:CGRectMake(0.0f, 0.0f, 320.0f, 480.0f)];
    // ...
    self.modalTransitionStyle = UIModalTransitionStylePartialCurl;
    [self presentModalViewController:mainMenuViewController animated:YES];
}

And the code you show has some mistakes:

self.modalTransitionStyle= UIModalTransitionStylePartialCurl;
[self popToViewController:element animated:YES];

self.modalTransitionStyle= UIModalTransitionStylePartialCurl; if you set this one, you need use

[self presentModalViewController:yourViewController animated:YES];

not

[self popToViewController:element animated:YES];

ios: Navigation to another screen using modalTransitionsytle attribute, crashes the app

2 Answers