UISegmentedControl Best Practice

Question

I\'m trying to work out the \"best\" way to use a UISegmentedControl for an iPhone application. I\'ve read a few posts here on stackoverflow and seen a few peo

Answer 1

I'd go with the second option you mention, creating the subviews in IB and swapping them in and out of a main view. This would be a good opportunity to use UIViewController, unsubclassed: in your initial setup, create a controller using -initWithNibName:bundle: (where the first parameter is the name of the NIB containing the individual subview, and the second parameter is nil) and add its view as a subview of your main view as necessary. This will help keep your memory footprint low: the default behavior of a UIViewController when receiving a memory warning is to release its view if it has no superview. As long as you remove hidden views from the view hierarchy, you can keep the controllers in memory and not worry about releasing anything.

(edited in response to comment:)

You don't need to subclass UIViewController, but you do need separate XIBs for each view. You also don't need to add anything to the containing view in IB.

Instance variables, in the interface of whatever class is handling all this:

 UIViewController *controllerOne;
 UIViewController *controllerTwo;

 UIViewController *currentController;

 IBOutlet UIView *theContainerView;

In your setup (-applicationDidFinishLaunching: or whatever)

 controllerOne = [[UIViewController alloc] initWithNibName:@"MyFirstView" bundle:nil];
 controllerTwo = [[UIViewController alloc] initWithNibName:@"MySecondView" bundle:nil];

To switch to a controller:

 - (void)switchToController:(UIViewController *)newCtl
 {
      if(newCtl == currentController)
           return;
      if([currentController isViewLoaded])
           [currentController.view removeFromSuperview];

      if(newCtl != nil)
           [theContainerView addSubview:newCtl.view];

      currentController = newCtl;
 }

Then just call that with, e.g.,

 [self switchToController:controllerOne];