Add a button like UIBarButtonItem to the center of Navigation Bar

This is how you programmatically add a button like UIBarButtonItem to the center of Navigation Bar:

UISegmentedControl *button = [[UISegmentedControl alloc]\\
 initWithItems:[NSArray arrayWithObjects:\\
LS(@"Folders"), nil]];
    button.frame = CGRectMake(0, 0, 100, 30);
    button.center = self.view.center;
    button.momentary = YES;
    button.segmentedControlStyle = UISegmentedControlStyleBar;
    button.tintColor = UIColorFromRGB(0x0000DD);
    [button addTarget:self action:\\
@selector(foldersClicked) forControlEvents:\\
UIControlEventValueChanged];
    self.navigationItem.titleView = button;