Question

I’m trying to create a push-on-push-off-like button with custom images in Xcode4 for iOS.
The code I’m using is

- (IBAction)btnAll:(id)sender
{
    UIButton *button = (UIButton *)sender;
    button.selected = !button.selected;
}

That works fine for now.
But my problem is, that when I’m toggling on, I press it on, then it is popping off again and then finally on.
The app works, but that is really ugly, though.

I firstly set the “highlighted” image to on. So when I highlight the button, it is on and that popping to on. That works fine. But when I turn it off again, the problem is the same, in the reverse direction.

I tried to put that code:

- (IBAction)btnAll:(id)sender
{
    UIButton *button = (UIButton *)sender;
    if(button.selected)
    {
        [button setImage[UIImage imageNamed@"off.png"] forState:UIControlStateHighlighted];
    }
    else
    {
        [button setImage[UIImage imageNamed@"on.png"] forState:UIControlStateHighlighted];
    }
    button.selected = !button.selected;
}

But as long button.selected = !button.selected there is no difference.
So it won’t make any change.

I also tried to trigger the IBAction on »Touch Down« but you can imagine how frustrating this will look like.

Has anybody got a solution for that problem?
Did anybody struggle with that one too?

Greets, thanks a lot
Julian

Answer 1

I’ve had a similar problem to this before, the button works a little strangely when tapping. Try this code and let me know if it works

    UIButton *button = (UIButton *)sender;
    if(button.selected)
    {
        [button setImage:[UIImage imageNamed:@"off.png"] forState:UIControlStateHighlighted];
        [button setImage:[UIImage imageNamed:@"off.png"] forState:UIControlStateSelected];
        [button setImage:[UIImage imageNamed:@"off.png"] forState:UIControlStateHighlighted | UIControlStateSelected];
    }
    else
    {
        [button setImage:[UIImage imageNamed:@"on.png"] forState:UIControlStateHighlighted];
        [button setImage:[UIImage imageNamed:@"on.png"] forState:UIControlStateSelected];
        [button setImage:[UIImage imageNamed:@"on.png"] forState:UIControlStateHighlighted | UIControlStateSelected];
    }
    button.selected = !button.selected;

    If (button.selected) {
      [button setImage:[UIImage imageNamed:@"on.png"] forState:UIControlStateNormal];
    } else {
      [button setImage:[UIImage imageNamed:@"off.png"] forState:UIControlStateNormal];
    }

When you tap and hold on a button the state is actually Highlighted & Selected so you need an image for both Highlight and selected state.