How to have a UIButton image change when a button is touched - objective-c

Question

I'm trying to have the UIButton image change when a button is touched. Currently I it changes but only on the highlighted state change. I would like it to change and stay there. I tried UIControlStateSelected for the state change but no luck.
thanks for the help
here's my code:
// Create buttons for the sliding category menu.
NSMutableArray* buttonArray = [NSMutableArray array];
NSArray * myImages = [NSArray arrayWithObjects:#"category-cafe-unsel.png", #"category-food-unsel.png", #"category-clothing-unsel.png", #"category-health-unsel.png", #"category-tech-unsel_phone.png" , #"category-tech2-unsel.png", #"catefory-theatre-unsel.png", #"category-travel-unsel.png", nil];
NSArray * myImagesSel = [NSArray arrayWithObjects:#"category-cafe-sel.png", #"category-food-sel.png", #"category-clothing-sel.png", #"category-health-sel.png", #"category-tech-sel_phone.png" , #"category-tech2-sel.png", #"catefory-theatre-sel.png", #"category-travel-sel.png", nil];
// only create the amount of buttons based on the image array count
for(int i = 0;i < [myImages count]; i++)
{
// Custom UIButton
btn = [UIButton buttonWithType:UIButtonTypeCustom];
[btn setFrame:CGRectMake(0.0f, 20.0f, 52.0f, 52.0f)];
[btn setTitle:[NSString stringWithFormat:#"Button %d", i] forState:UIControlStateNormal];
[btn setImage:[UIImage imageNamed:[myImages objectAtIndex:i]] forState:UIControlStateNormal];
[btn setImage:[UIImage imageNamed:[myImagesSel objectAtIndex:i]] forState:UIControlStateHighlighted];
NSLog(#"The button title is %# ", btn.titleLabel.text);
[btn addTarget:self action:#selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside];
[buttonArray addObject:btn];

Answer 1

In your IBAction method add the following lines:
- (IBAction)change:(id)sender
{
UIButton *button = (UIButton *)sender;
int tagOfButton = button.tag - 1;
[button setImage:[UIImage imageNamed:[myImagesSel objectAtIndex:tagOfButton]] forState:UIControlStateNormal];
}
Add a single line to your for loop like:
for(int i = 0;i < [myImages count]; i++)
{
// other stuffs
btn.tag = i+1;
}
EDIT:
If you need to undone the previous selection when other button is clicked:
write this loop inside your IBAction method.
for(int i = 0;i < [myImages count]; i++)
{
UIButton *but = (UIButton *)[buttonArray objectAtIndex:i];
if(but != button)
{
[btn setImage:[UIImage imageNamed:[myImages objectAtIndex:i]] forState:UIControlStateNormal];
}
}
Or simply store the previous button tag to a variable.
And use it to change undone the image change.

Answer 2

[btn setTitle:#"I'm not selected" forState:UIControlStateNormal];
[btn setImage:[UIImage imageNamed:[myImages objectAtIndex:i]] forState:UIControlStateNormal];
[btn setTitle:#"I'm selected" forState:UIControlStateSelected];
[btn setImage:[UIImage imageNamed:[myImagesSel objectAtIndex:i]] forState:UIControlStateSelected];
[btn addTarget:self action:#selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside];
-(IBAction)buttonPressed:(id)sender {
btn.selected = !btn.selected;
}