In IOS 4.x or lower, viewDidAppear method is not getting called while adding subview to a view, why?

10
votes

In iOS 4.x or lower, viewDidAppear and viewWillAppear, viewDidDisappear and viewWillDisappear, such ViewController's delegate methods are not getting called. The same methods work fine with the iOS 5.x.

Why? Is it a bug in iOS 4.x or lower. Because in iOS 5.x all those methods gets called in proper manner and sequence.

Thanks in advance, Mrunal

2
ios4delegatesuiviewcontrollerios5viewwillappear
Could you explain how you come to his conclusion ? Do you log something from these methods which do show in iOS5 but not in iOS4 ? - teriiehina
Yes I have used NSLog also and Breakpoints also... Tried also on both simulator as well on device. - Mrunal
This depends on you viewController hierarchy that how are you managing your content viewController and Container viewController. - fibnochi
means? how to manage view hierarchy for that.. - Mrunal

2 Answers

3
votes

For IOS4.x i use the UINavigationController delegate methods like this:

-(void)navigationController:(UINavigationController *)navigationController didShowViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    if (SYSTEM_VERSION_LESS_THAN(@"5.0")) {
        [activeView viewDidAppear:YES];
    }
}
-(void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    if (SYSTEM_VERSION_LESS_THAN(@"5.0")) {
        [activeView viewWillAppear:YES];
    }
}

I hope this helps!

2
votes

If your view controller is a child of another view controller, (i.e. it's a UINavigationController inside a UIViewController, or vice versa, etc.), the child's viewDidAppear, viewWillAppear, etc. methods will not get called. The solution is to have the parent call into them like:

-(void)viewWillAppear:(BOOL)animated { 
    [super viewWillAppear:animated];
    [child viewWillAppear:animated];
}

I know this happens through iOS 4.3. In iOS 5 there is a new set of methods specifically for handling these cases: Implementing a Container View Controller