How To animate image using uibuttons - iphone

Question

I have three uibuttons named 1,2 and 3 and right at the bottom of those buttons i have an arrow image which indicates that which is the current button pressed.
I want that when i press any of the button the arrow starts animating and slides at the bottom of the button which is pressed.

Answer 1

(void)setImage:(UIImage *)image forState:(UIControlState)state;
and select UIControlState from
enum {
UIControlStateNormal = 0,
UIControlStateHighlighted = 1 << 0, // used when UIControl isHighlighted is set
UIControlStateDisabled = 1 << 1,
UIControlStateSelected = 1 << 2, // flag usable by app (see below)
UIControlStateApplication = 0x00FF0000, // additional flags available for application use
UIControlStateReserved = 0xFF000000 // flags reserved for internal framework use
};
typedef NSUInteger UIControlState;

Answer 2

Hook all your buttons up to one method or in the method that responds to each of the button clicks call this method as well.
- (IBAction)buttonTapped:(UIButton *)sender;
{
CGPoint center = self.indicator.center;
center.x = sender.center.x;
[UIView animateWithDuration:0.25f
animations:^{
self.indicator.center = center;
}];
}

Answer 3

Do the following in your button pressed method:
// For Button 1
- (IBAction)pressedButton1:(id)sender{
// Create an animation lasting 1 second
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:1.00];
[UIView setAnimationDelegate:self];
// Set your arrow image view's center x property to that of the button
myArrowImageView.center = CGPointMake(myButton1.center.x, myArrowImageView.center.y);
[UIView commitAnimations];
}
// For Button 2
- (IBAction)pressedButton2:(id)sender{
// Create an animation lasting 1 second
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:1.00];
[UIView setAnimationDelegate:self];
// Set your arrow image view's center x property to that of the 2nd button
myArrowImageView.center = CGPointMake(myButton2.center.x, myArrowImageView.center.y);
[UIView commitAnimations];
}
// For Button 3
- (IBAction)pressedButton3:(id)sender{
// Create an animation lasting 1 second
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:1.00];
[UIView setAnimationDelegate:self];
// Set your arrow image view's center x property to that of the 3rd button
myArrowImageView.center = CGPointMake(myButton3.center.x, myArrowImageView.center.y);
[UIView commitAnimations];
}
P.S. its always good to also post some source code when you ask a question. This helps people to give you a better answer.