Why is this UIButton still triggering event hander while disabled

Question

I have a UIButton in a view. I attach an Event handler to it like this:

[self.button addTarget:self  
           action:@selector(button_touchUpInside:)      
 forControlEvents:UIControlEventTouchUpInside];

The handler looks like this:

-(void) button_touchUpInside:(id)sender
{
    NSLog(@"%@", ((UIButton *)sender).enabled ? @"ENABLED" : @"DISABLED"); // Logs DISABLED
   // Do stuff
}

I disable the button like this:

-(void)setEnabled:(BOOL)enabled
{
    enabled_ = enabled;
    self.button.enabled = enabled;
}

My problem is that even after I set enabled = NO on the button a TouchUpInside still triggers the handler. I can see in the handler that the button is disabled, however the handler is still triggered.

Please note that there are several ways of working around this - checking for button.enabled in the handler, @sanchitsingh's answer below etc. WHat I want to know is why this is happening.

Your NSLog statement is incorrect. It should be like below: NSLog(@"%@", ((UIButton *)sender).enabled ? @"ENABLED" : @"DISABLED"); — Apurv, Jul 09 '12 at 10:54
Did you associate button_touchUpInside: with any other UI item's action? — Hermann Klecker, Jul 09 '12 at 10:58
@Nuzhat Zari Added it, but the fact that I can see the button is disabled in the handler shows that the button was definitely set correctly to be disabled. — Undistraction, Jul 09 '12 at 10:59
My question was where you are setting it to NO, can you please post the entire code where you are creating button? — Nuzhat Zari, Jul 09 '12 at 11:06
And you calling -(void)setEnabled:(BOOL)enabled?Or may be you are calling -(void)setEnabled:(BOOL)enabled and sending YES as parameter somewhere in the code. — Nuzhat Zari, Jul 09 '12 at 11:21
@NuzhatZari Yes. It's called from the UIViewController much earlier in response to a model changing. — Undistraction, Jul 09 '12 at 11:23
My suggestion is just put NSLog inside -(void)setEnabled:(BOOL)enabled and print latest parameter value passed YES/NO. — Nuzhat Zari, Jul 09 '12 at 11:25
@NuzhatZari I've done this already. Button is disabled a single time. — Undistraction, Jul 09 '12 at 11:29

score 4 · Answer 1 · answered Jul 09 '12 at 13:01

4

Just check if there is any gesture involved in your code. That could cause a problem. I think you should just use

 button.enabled = NO;
 button.userInteractionEnabled = NO;

answered Jul 09 '12 at 13:01

khushalbokadey

1,132
1
11
25

There are no Gesture Recognisers used anywhere. – Undistraction Jul 09 '12 at 14:02

score 4 · Accepted Answer · edited May 23 '17 at 12:27

4

From my personal experience, from this question, and others thread across the web, it seems that Apple's documentation about UIControl.enabled is incorrect, and that setting a UIControl disabled doesn't prevent it from getting touch events. It only neutralizes a few events such as (from memory, can't check now) click, touch down, and current action-triggering events, so you effectively have to use UserInteractionEnabled property to really get rid of touch events.

edited May 23 '17 at 12:27

Community

1
1

answered Jul 10 '12 at 07:06

psycho

631
10
27

1

But Apple don't make mistakes ;) – Undistraction Jul 10 '12 at 08:53

score 1 · Answer 3 · answered Jul 09 '12 at 10:56

1

Try this

button.userInteractionEnabled=NO;

answered Jul 09 '12 at 10:56

Sanchit Paurush

6,114
17
68
107

Thanks. I know how to work around this, but I'm trying to understand what might be causing it. – Undistraction Jul 09 '12 at 11:00

Why is this UIButton still triggering event hander while disabled

3 Answers3