Xcode (Objective C) - Error regarding interface? - ios

Question

I'm a beginner to Xcode nd Objective-C! I'm making an ios app which is basically a stop watch. The idea is only to have two buttons. One to reset the stopwatch and the other to start and stop the clock. (Basically, you click the start button which then turns into a stop button which when clicked will stop the stopwatch. The problem is I have two errors which are the same and read the following: (I don't know how to fix them which is the question!)
No visible #interface fro 'UIButton' declares the selector 'setTitle:forControlState:'
This has come up twice at two points! Point one:
[button setTitle:#"Start" forControlState:UIControlStateNormal];
And point two...
[button setTitle:#"Stop" forControlState:UIControlStateNormal];
Here is my code for VeiwController.h:
//
#import <UIKit/UIKit.h>
float addingtheTime;
#interface ViewController : UIViewController
{
IBOutlet UILabel *Label;
NSTimer *Timer;
}
#end
Here is my code for ViewController.m
//
#import "ViewController.h"
#interface ViewController ()\
#end
#implementation ViewController
-(IBAction)Start:(id)start
{
UIButton *button = (UIButton *)start;
if (button.tag == 0){
button.tag = 1;
[button setTitle:#"Start" forControlState:UIControlStateNormal];
Timer = [NSTimer scheduledTimerWithTimeInterval:0.01 target:self selector:#selector(addingthetime) userInfo:nil repeats:YES];
}else {
button.tag = 0;
[button setTitle:#"Stop" forControlState:UIControlStateNormal];
//Invoke your method to stop Timer.
}
}
-(IBAction)Restart:(id)sender
{
[Timer invalidate];
addingtheTime = 0;
Label.text = [NSString stringWithFormat:#"0.00"];
}
-(void)addingthetime
{
addingtheTime = addingtheTime + 0.01;
Label.text = [NSString stringWithFormat:#"%.2f", addingtheTime];
}
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
#end
Please note I am a beginner so please explain as much as you can and thanks you in advance for any help!!!

Answer 1

its forstate not forControlState
[button setTitle:#"start" forState:UIControlStateNormal];
[button setTitle:#"stop" forState:UIControlStateNormal];