IOS/Objective-C: Animate Image Change in UIBarButtonItem - ios

Question

I am trying to create an effect where a custom image in a UIBarButtonItem changes to another image. So far, I have been able to get the first image to dissolve with the following code. Can anyone suggest how I could get the second image to fade in at the same time?
//Create barbuttonitem in viewwillappear
UIButton *b = [UIButton buttonWithType:UIButtonTypeCustom];
[b setFrame:CGRectMake(12, 0, 22, 22)];
[b addTarget:self action:#selector(menuButtonPressed:) forControlEvents:UIControlEventTouchUpInside];
[b setImage:[UIImage imageNamed:#"firstimage.png"] forState:UIControlStateNormal];
UIBarButtonItem * myBarButton = [[UIBarButtonItem alloc] initWithCustomView:b];
//Animate in viewDidAppaer
[UIView animateWithDuration:1.0
delay:1.0
options:UIViewAnimationOptionCurveEaseIn
animations:^{
self.myBarButton.customView.alpha = 0;
}
completion:^(BOOL finished) {
UIImage *secondImage = [UIImage imageNamed:#"menu2.png"];
[self.myBarButton setImage:secondImage];//THis does not change image
self.myBarButton.customView.alpha = 1;//no animation
}];

Answer 1

You can use something like this
[UIView transitionWithView:self.myBarButton
duration:0.3
options:UIViewAnimationOptionTransitionCrossDissolve
animations:^{ [self.myBarButton setImage:secondImage];}
completion:nil];

Answer 2

Try this code
#interface ViewController ()
{
UIBarButtonItem * myBarButton;
NSTimer *time;
UIButton *b;
}
#end
#implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
b = [UIButton buttonWithType:UIButtonTypeCustom];
[b setFrame:CGRectMake(12, 0, 22, 22)];
[b addTarget:self action:#selector(menuButtonPressed:) forControlEvents:UIControlEventTouchUpInside];
[b setImage:[UIImage imageNamed:#"AddPlus_Yellow.png"] forState:UIControlStateNormal];
myBarButton = [[UIBarButtonItem alloc] initWithCustomView:b];
self.navigationItem.rightBarButtonItem=myBarButton;
time = [NSTimer scheduledTimerWithTimeInterval: 2.0 target: self selector:#selector(onTick:) userInfo: nil repeats:NO];
// Do any additional setup after loading the view, typically from a nib.
}
-(void)onTick:(NSTimer *)timer {
[b setImage:[UIImage imageNamed:#"filter.png"] forState:UIControlStateNormal];
[time invalidate];
}