CODEWITHSUNDEEP
iosobjective-c
duckisaurusRex
duckisaurusRex

Reputation: 33

iOS use of declared identifier in buttons

I'm a very new to iOS development but I have dabbled in Java and C before.

I'm trying to create a simple timer application and when the user presses 'start', the button text will turn into 'reset' but the compiler throws me a "Use of undeclared identifier 'btnStart'"

I've taken out the rest of the code because everything worked run until I tried to change the button text.

I'm pretty sure its correctly declared in the .h file and I'm thinking it might have to do with adding another @property argument for the button itself but that didn't really work. How do I properly declare a button then?

Thanks

my ViewController.m

- (IBAction)btnStart:(id)sender {

   [btnStart setTitle: @"RESET" forState: UIControlStateNormal]; //Error shown here
}

my ViewController.h

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController

@property (weak, nonatomic) IBOutlet UILabel *lblDisplay;

- (IBAction)btnStart:(id)sender;
- (IBAction)btnStop:(id)sender;

@end

Upvotes: 3

Views: 336

Answers (3)

Mayank Barnwal
Mayank Barnwal

Reputation: 123

You can set title of the button for two states in viewDidLoad function like this 

[btnStart setTitle: @"RESET" forState: UIControlStateNormal];
[btnStart setTitle: @"Start" forState: UIControlStateSelected];

and in your function use this code

- (IBAction)btnStart:(id)sender {
UIButton *btn = (UIButton*)sender;
[btn setSelected:!btn.isSelected];
}

Upvotes: 0

Bannings
Bannings

Reputation: 10479

The sender should be the button itself. Try this

- (IBAction)btnStart:(UIButton *)sender {
   [sender setTitle: @"RESET" forState: UIControlStateNormal];
}

Upvotes: 2

ashForIos
ashForIos

Reputation: 399

Please declare button IBOutlet in .h or .m file where you have declared --

@property (weak, nonatomic) IBOutlet UILabel *lblDisplay;

@property (weak, nonatomic) IBOutlet UIButton *btnStart;

and use it like this 

   [self.btnStart setTitle: @"RESET" forState: UIControlStateNormal];

Upvotes: 1

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