“Variable Undeclared” error when compiling to iOS Device, but not for Simulator

Question

I have an custom UIVIewController that is the base class for other controllers and has an instance of a custom UIView variable that is accessed by inherited the classes.

Answer 1

I just stumble upon your method declaration

-(void)loadView { ... }

In a view the first point you can rely that everything is fully initialized is after -(void)viewDidLoad was called. Maybe your code works on the simulator because your Mac is fast enough to cope this speed issue - but your mobile device isn't.

Maybe try this coding:

Your BaseViewController.h file:

@interface BaseViewController : UIViewController {
    UIView *_vwHeader;
}
@end

Your BaseViewController.m file:

#import "BaseViewController.h"
@implementation BaseViewController

-(void)viewDidLoad {
    [super viewDidLoad];
    _vwHeader = [[UIView alloc] init];
}

Your CustomViewController.h file:

@interface CustomViewController : BaseViewController {
}
@end

Your CustomViewController.m file:

#import "CustomViewController.h"

-(void)viewDidLoad {
    [super viewDidLoad];
    [_vwHeader setHidden:NO];
}

Now your CustomViewController can rely on every instance variable in BaseViewController is correctly instantiated.