iPhone - UISegmentedControl segment width = 0?

Question

I have a UISegmentedControl with 3 segments and I want to change the width of one segment 1 when the user chooses any segment. Here is the code:

// the UISegmentedControl is created
[segmentedControl addTarget:self action:@selector(changeIt:) 
               forControlEvents:UIControlEventValueChanged];

//... 

// and this is the changeIt method:


- (void) changeIt:(id)sender {

    // discover the original width of segment 1, to restore it later
    UISegmentedControl *seg = (UISegmentedControl*)sender;
    CGFloat segWidth = [seg widthForSegmentAtIndex:1];
    // At this point segWidth = 0 ?????????????????
    // note: seg is not nil at this point. Printing seg to console shows it is
    // a valid UISegmentedControl...

}

Any clues? Thanks.

Answer 1

Documentation says "The default value is {0.0}, which tells UISegmentedControl to automatically size the segment."