Question

I have placed a pause button in UI, where when the user clicks the button, the image of button from pause image it has to change to the start image. I have placed both the start and the pause images in the bundle, I am able to do this,but when i click on start again , it should show pause image button,How to do this, the following is the code i am using,

-(IBAction)btnClked:(id)sender
{

    [pauseButton setImage:[UIImage imageNamed:@"pause.png"] forState:UIControlStateNormal];



    UIButton *btn=(UIButton *)sender;


    [btn setImage:[UIImage imageNamed:@"start.png"] forState:UIControlStateNormal];
}

Answer 1

You need a variable to keep track of that state change. A BOOL is fine.

But using your code, you can “abuse” the tag property of UIButton to tell if it’s playing (tag == 1) or paused (tag == 0)

-(IBAction)btnClked:(id)sender {
     UIButton *btn=(UIButton *)sender;
     if (btn.tag == 1) {
         btn.tag = 0;
         [btn setImage:[UIImage imageNamed:@"pause.png"] forState:UIControlStateNormal];
     } else {
         btn.tag = 1;
        [btn setImage:[UIImage imageNamed:@"start.png"] forState:UIControlStateNormal];
     }
}