Disabling and Enabling a button on event iOS

Question

I have a stopclock app and would like for the startCountButton button to be disabled when it is initially pressed and then once the stopCountButton button is pressed for it to be enabled again so that the start button can only be pressed once. Here is my code

- (IBAction)startCount:(UIButton*)sender {
    countInt = 0;
    self.label.text = [NSString stringWithFormat:@"%i", countInt];
    timer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(countTimer) userInfo:nil repeats:YES];
}

- (IBAction)stopCount:(UIButton*)sender {
    countInt = 0;
    [timer invalidate];
}

-(void)countTimer {
    countInt += 1;
    self.label.text = [NSString stringWithFormat:@"%i", countInt];
}

Any help on what I would need to add? I am not looking to change text, just disabling it

What's your question? What is preventing you from doing what you are stating? — rmaddy, Dec 14 '15 at 15:17

score 6 · Accepted Answer · edited Dec 14 '15 at 15:28

6

First, you need a reference to the button. Then, add the following code to startCount::

((UIButton *)sender).enabled = NO

and in stopCount: add:

startCountButton.enabled = YES

edited Dec 14 '15 at 15:28

Slipp D. Thompson

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answered Dec 14 '15 at 15:14

dasdom

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When I add this two lines, I get the following error message: `Use of undeclared identifier 'startCount'` – peterbonar Dec 14 '15 at 15:18
@peterbonar What? Those two lines do not have the word `startCount` in them. What did you add? – dasdom Dec 14 '15 at 15:20
The button is not called `startButton` – peterbonar Dec 14 '15 at 15:21
Yes, the button is also called `startCount` – peterbonar Dec 14 '15 at 15:23
I have already said above that it produces an error message – peterbonar Dec 14 '15 at 15:25
@peterbonar Rename your buttons `startCountButton` & `stopCountButton`. That's much more in-line with Obj-C naming standards & best practices. – Slipp D. Thompson Dec 14 '15 at 15:26
@peterbonar Have you added a reference to the button, as I wrote in my answer? If so, show the code with the reference. If not, do it. – dasdom Dec 14 '15 at 15:26
Got it, thanks @dasdom – peterbonar Dec 14 '15 at 15:28

score 1 · Answer 2 · edited Dec 14 '15 at 15:23

1

Both startCount: and stopCount: accept a UIButton as their parameter, but I'm confused as to how the second one gets called.

If startCount: is called by the button you want to disable, you can just write this:

sender.enabled = NO;

But stopCount: is tricky, because clearly it can't be called by the button as it was disabled a moment ago. If stopCount: is being called from a different button (as I guess it must be) then you must store a reference to the first button in order to re-enable it. You can then do:

self.disabledButton.enabled = YES;

edited Dec 14 '15 at 15:23

Slipp D. Thompson

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answered Dec 14 '15 at 15:14

TwoStraws

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`enabled` is better because (depending on the button type used) it fades out the button as well. – dasdom Dec 14 '15 at 15:15
1

Ha! I was just making that exact change :) – TwoStraws Dec 14 '15 at 15:16

score 0 · Answer 3 · edited Dec 14 '15 at 15:29

0

With enable propriety you can enable/disable a button:

startCountButton.enabled = NO

edited Dec 14 '15 at 15:29

Slipp D. Thompson

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answered Dec 14 '15 at 15:12

chiarotto.alessandro

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The question is tagged Objective-C, not Swift. Please post answers in the appropriate language. – rmaddy Dec 14 '15 at 15:28

Disabling and Enabling a button on event iOS

3 Answers3