Changing image on UIButton when user presses that button on an iPhone - iphone

Question

I want to change the image on UIButton, when User presses that button. So, I wrote
btnthumbnail2 setImage:[UIImage imageNamed:#"leaderboard_ov.png"] forState:UIControlStateNormal];
and after that I changed the view.
The image is changing but not display the changed image.I think the controll goes to next view tha's why it is happening. But I want to show the change, How can I do this?? Plz help me for this..

Answer 1

I am using Interface Builder, in which I added a UIButton to the view.
I defined the button selected by default and selected my image for the selected state (Use drop-down list in Inspector window to choose "Selected State Configuration" before selecting the image).
Create an IBAction in the controller and connect the button to that action.
Then see the code below:
-(IBAction) toggleUIButtonImage:(id)sender{
if ([sender isSelected]) {
[sender setImage:unselectedImage forState:UIControlStateNormal];
[sender setSelected:NO];
} else {
[sender setImage:selectedImage forState:UIControlStateSelected];
[sender setSelected:YES];
}
}

Answer 2

This is the simplest way that I am doing it and it works every time
-(void)buttonTouched:(id)sender
{
UIButton *btn = (UIButton *)sender;
if( [[btn imageForState:UIControlStateNormal] isEqual:[UIImage imageNamed:#"icon-Locked.png"]])
{
[btn setImage:[UIImage imageNamed:#"icon-Unlocked.png"] forState:UIControlStateNormal];
// other statements
}
else
{
[btn setImage:[UIImage imageNamed:#"icon-Locked.png"] forState:UIControlStateNormal];
// other statements
}
}
You can use other similar checks for other states such as SELECTED, ENABLED, HIGHLIGHTED.

Answer 3

The code you have there should work fine, but I'm guessing that the button image doesn't appear changed until the next run through the event loop, so you don't see it before the view gets switched out.
It's kind of a hack, but you could try delaying the view change just slightly so that the button will update.
So instead of this:
[btnthumbnail2 setImage:[UIImage imageNamed:#"leaderboard_ov.png"] forState:UIControlStateNormal];
[self showMyOtherView];
Try this:
[btnthumbnail2 setImage:[UIImage imageNamed:#"leaderboard_ov.png"] forState:UIControlStateNormal];
[self performSelector:#selector(showMyOtherView) withObject:self afterDelay:0.01];

Answer 4

To change the image for the selected state you have to call setImage for state UIControlStateSelected. You can set separate images for different states (Normal, Highlighted, Disabled, Selected, etc).

Answer 5

If you want to change the image when the button is clicked, this way, works perfectly:
-(IBAction)buttonClicked: (id)sender
{
UIButton *buttonObj = (UIButton*)sender;
[buttonObj setBackgroundImage:[UIImage imageNamed:#"myImage.png"]
forState:UIControlStateNormal];
}

Answer 6

The simplest way to accomplish this is to simply set the highlighted image in Interface Builder.

Answer 7

Building on Nicsoft's answer.
-(void)viewDidLoad {
[super viewDidLoad];
[self.button setImage:[UIImage imageNamed:#"unselectedImageName"] forState:UIControlStateNormal];
[self.button setImage:[UIImage imageNamed:#"selectedImageName"] forState:UIControlStateSelected];
}
-(IBAction)toggleButton:(UIButton *)sender {
sender.selected = !sender.selected;
// Add logic here
}

Answer 8

I wrote code that does exactly this last night, and I didn't have to resort to any strange delaying tactics. In this particular case, I'm doing it from inside a tableViewCell. This is more code than you asked for, but it shows the whole process I used. As you can see, I chose not to have any special image for the period of time DURING a button touch.
// Button set up, inside cellForRowAtIndexPath:
// imageFrame is just the rect that you want the button to occupy
[self setFavorite:[[UIButton alloc] initWithFrame:imageFrame]];
[[self favorite] addTarget:self action:#selector(toggleFavorite:)
forControlEvents:UIControlEventTouchUpInside];
[cell addSubview:[self favorite]];
[self draw];
// definition of the callback specified above
- (void) toggleFavorite:(id) sender {
if (favoriteState == 0 ){
favoriteState = 1;
} else {
favoriteState = 0;
}
[self draw];
}
// the draw method, to set the images
// favOn and favOff are statically defined at the top of the class
- (void) draw {
if (favoriteState != 0) {
[[self favorite] setBackgroundImage:favOn forState:UIControlStateNormal];
[[self favorite] setBackgroundImage:favOn forState:UIControlStateHighlighted];
} else {
[[self favorite] setBackgroundImage:favOff forState:UIControlStateNormal];
[[self favorite] setBackgroundImage:favOff forState:UIControlStateHighlighted];
}
}

Answer 9

Hate to add to the plethora of answers, but:
Select images in IB for the button's default and selected states.
Connect an IBAction and keep it simple.
#IBAction func buttonTapped(sender: UIButton){sender.selected = !sender.selected}
Done.