Flashlight Dimming Error

Question

When I put your flashlight dimmer coding into my app, I get this error "local declaration 'slider' hides instance variable"

Here is the code:

UISlider *slider = [[UISlider alloc] initWithFrame:CGRectMake(20.0f, 20.0f, 280.0f, 40.0f)];
slider.maximumValue = 1.0f;
slider.minimumValue = 0.0f;
[slider setContinuous:YES];
[slider addTarget:self action:@selector(sliderDidChange:) forControlEvents:UIControlEventValueChanged];
[self.view addSubview:slider];

possible duplicate of [Local declaration 'theslider' hides instance variable](http://stackoverflow.com/questions/15672821/local-declaration-theslider-hides-instance-variable) — jscs, Apr 03 '13 at 19:21
rename your _local_ variable (to e.g. `slider1`) and your problem will be resolved; or use the global `slider` property instead of creating a new _local_ variable. — holex, Jan 15 '16 at 10:02

score 0 · Answer 1 · answered Apr 02 '13 at 18:10

0

The error means there is a variable named slider somewhere in your app that is already declared. If you simply rename your variable, the error should go away.

And for Steve's sake, please don't make another flashlight app!

answered Apr 02 '13 at 18:10

woz

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score 0 · Answer 2 · answered Apr 02 '13 at 18:11

0

"local declaration 'slider' hides instance variable"

This is straight forward. You need to change either of the name,

Preferably change local slider to someother name as:

UISlider *localSlider = [[UISlider alloc] initWithFrame:CGRectMake(20.0f, 20.0f, 280.0f, 40.0f)];
UISlider *slider = [[UISlider alloc] initWithFrame:CGRectMake(20.0f, 20.0f, 280.0f, 40.0f)];
localSlider .maximumValue = 1.0f;
localSlider .minimumValue = 0.0f;
[localSlider setContinuous:YES];
[localSlider addTarget:self action:@selector(sliderDidChange:) forControlEvents:UIControlEventValueChanged];
[self.view localSlider];

answered Apr 02 '13 at 18:11

Anoop Vaidya

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When i changed the slider to local slider it then says unused variable?? – Spencer Whitney Apr 02 '13 at 18:14
You need to change all the local `slider` to `localSlider` – Anoop Vaidya Apr 02 '13 at 18:15
- (void)sliderDidChange:(UISlider *)slider says undeclared identifier 'sliderdidchange' – Spencer Whitney Apr 02 '13 at 18:21
in that method you are using that name which is not declared. – Anoop Vaidya Apr 02 '13 at 18:22
show the full code, better to ask a new question if it is tooo long – Anoop Vaidya Apr 02 '13 at 18:24
- (void)sliderDidChange:(UISlider *)slider { AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]; [device lockForConfiguration:nil]; [device setTorchModeOnWithLevel:slider.value error:NULL]; [device unlockForConfiguration]; } – Spencer Whitney Apr 02 '13 at 18:25
it says it for - (void)sliderDidChange:(UISlider *)slider – Spencer Whitney Apr 02 '13 at 18:25

score 0 · Answer 3 · answered Apr 02 '13 at 18:16

0

You have declared your local variable 'slider' with the same name as a previously declared instance variable. You need to either change the name of the instance variable, or the local variable, and all will be well.

answered Apr 02 '13 at 18:16

codeqi

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Flashlight Dimming Error

3 Answers3