UIBarButtonItem:setBackgroundVerticalPositionAdjustment not working properly with custom button - iphone

Question

I have the following code to customize the display of an UIBarButtonItem (locationButton):
UIButton *locationButtonAux = [UIButton buttonWithType:UIButtonTypeCustom];
[locationButtonAux setFrame:CGRectMake(0, 0, LOCATION_BUTTON_WIDTH, LOCATION_BUTTON_HEIGHT)];
[locationButtonAux setBackgroundImage:[UIImage imageNamed:#"location_button.png"] forState:UIControlStateNormal];
[locationButtonAux setBackgroundImage:[UIImage imageNamed:#"location_button.png"] forState:UIControlStateHighlighted];
[locationButtonAux addTarget:self action:#selector(userLocation) forControlEvents:UIControlEventTouchUpInside];
UIBarButtonItem *locationButton = [[UIBarButtonItem alloc] initWithCustomView:locationButtonAux];
UIBarButtonItem * item = [[UIBarButtonItem alloc] initWithTitle:#"title"
style:UIBarButtonItemStyleDone
target:nil action:#selector(someMssage)];
[locationButton setBackgroundVerticalPositionAdjustment:-20.0 forBarMetrics:UIBarMetricsDefault];
self.navigationItem.rightBarButtonItem = locationButton;
And I want to adjust the position of this button into the NavigationBar, because my NavigationBar is taller than normal (is customized using Appeareance).
I'm using the method setBackgroundVerticalPositionAdjustment, as you can see in the code, to do that. But is not working at all with my UIBarButtonItem, no matter what offset I put there, the button always appear close to the bottom of the bar (snapshot).
BUT, if I use a normal UIBarButtonItem with a normal style (the one I called button) I DO can see how the position of the button will be altered the offset of -20. Very strange... Any ideas?
Thank you!

Answer 1

Perhaps something like this would work for you:
UIView *rightView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 150, 30)]; //change this frame to counteract for your taller navbar
[rightView addSubview:locationButtonAux];
UIBarButtonItem *rightBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:rightView];
self.navigationItem.rightBarButtonItem = rightBarButtonItem;
Hope this helps

Answer 2

You need to put the button inside a blank view and position it within that blank view. Now make that view the custom view of the bar button item.
You really don't need a button here, since this is just an image and you are not using any of the button capabilities (you can attach a gesture recognizer to spot the tap). So here's a simple solution using an image view:
UIImageView *locationButtonAux =
[[UIImageView alloc] initWithImage:[UIImage imageNamed:#"location_button.png"]];
UIView* v = [[UIView alloc] initWithFrame:locationButtonAux.frame];
[v addSubview:locationButtonAux];
CGRect f = locationButtonAux.frame;
f.origin.y -= 10;
locationButtonAux.frame = f;
UIBarButtonItem *locationButton = [[UIBarButtonItem alloc] initWithCustomView:v];
self.navigationItem.rightBarButtonItem = locationButton;
I've omitted the gesture recognizer part but you can easily see how to add it.