无法在细分之间进行UISegment Control的切换

Question

Below is the code snippet I am using to set up my UISegment Control

//Add UIView below the nav bar
UIView *buttonContainer = [[UIView alloc]initWithFrame:CGRectMake(0, 0, 320, 30)];

[self.view addSubview:buttonContainer];

//Set up segment control
NSString *nicknameLabel = [NSString stringWithFormat:@"%@",self.nickname];

UISegmentedControl *tempSegmentControl = [[UISegmentedControl alloc]initWithItems:[NSArray arrayWithObjects:nicknameLabel,@"Friends", @"Everyone", nil]];
tempSegmentControl.frame = CGRectMake(-8, 44, 336, 30);

self.segmentControl = tempSegmentControl;
[self.segmentControl setWidth:112 forSegmentAtIndex:0];
[self.segmentControl setWidth:112 forSegmentAtIndex:1];
[self.segmentControl setWidth:112 forSegmentAtIndex:2];
self.segmentControl.selectedSegmentIndex = 0;
[self.segmentControl addTarget:self action:@selector(toggleControls:) forControlEvents:UIControlEventValueChanged];
[self.segmentControl setSegmentedControlStyle:UISegmentedControlStylePlain];

[self changeSegmentFontSize];

[tempSegmentControl release];
[buttonContainer addSubview:self.segmentControl];
[self.view bringSubviewToFront:buttonContainer];
[buttonContainer bringSubviewToFront:self.segmentControl];
[buttonContainer release];

However, I in the app, I am unable to switch between the segments for the segmented control. (only show default first segment highlighted)

Any advice on how I can fix this?

Answer 1

It looks like a bounds problem. The containing view has bounds {0, 0, 320, 30} while the segmented control has {-8, 44, 336, 30}. This means the segmented control is technically "outside" its containing view and the iOS hit test will not register a touch.

Try not setting the segmented control's frame (temporarily comment out the tempSegmentControl.frame = CGRectMake(-8, 44, 336, 30); line) and see what happens.

Answer 2

1. Check that userInteractionEnabled is set to TRUE for your view, buttonContainer, and segment control.

2. Check that the bounds of the buttonContainer's superview are wide and tall enough to fully contain the buttonContainer. If they're not then hit-testing wont work and the segmented control wont get any touches.