How can i add method to UINavigationbar back button, so whenever I click that back button I need to check some values and show UIAlertView? Is there any option for this?
i tried this method but its working for me
- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated
{
//show alert
}
and also this method but both are not woking
-(void) viewWillDisappear:(BOOL)animated {
if ([self.navigationController.viewControllers indexOfObject:self]==NSNotFound) {
// back button was pressed. We know this is true because self is no longer
// in the navigation stack.
NSLog(@"hi");
}
Yes you can
In viedDidLoad
UIBarButtonItem * backBtn = [[UIBarButtonItem alloc]initWithTitle:@"Back" style:UIBarButtonItemStyleBordered target:self action:@selector(goBackToAllPets:)];
self.navigationItem.leftBarButtonItem = backBtn;
write following function to check condition
-(void)goBackToAllPets:(id)sender
{
if(/*check condition*/)
{
UIAlertView *alert = [[UIAlertView alloc]initWithTitle:nil message:@"message" delegate:self cancelButtonTitle:@"No" otherButtonTitles:@"Yes", nil];
alert.tag = 0;
[alert show];
}
else
{
[self.navigationController popViewControllerAnimated:YES];
}
}
Suppose you have two controllers - Controller1 and Controller2.
Controller2 is pushed from Controller1. So before pushing the Controller2 on the navigationController from Controller1
Controller2 *controller2 = [[[Controller2 alloc] init]autorelease];
self.navigationItem.hidesBackButton = YES;
Now, in the viewDidLoad: method of Controller2, add the following snippet
UIBarButtonItem *backBarButtonItem =[[[UIBarButtonItem alloc]initWithTitle:@"Back" style:UIBarButtonItemStyleBordered target:self action:@selector(goBackToAllPets:)]autorelease];
self.navigationItem.leftBarButtonItem = backBarButtonItem;
and in the backButtonClicked method, you can perform the checks you want to.