UILabels Marquee + Overlapping while animating labels - iphone

Question

I wrote following code for adding marquee effect on labels being shown one bye one on a view.
- (void)marqueeMessage:(NSString *)messageString
{
UILabel *label = [[UILabel alloc] initWithFrame:(CGRectMake(520, 0, 480, 21))];
label.text = messageString;
[self.view addSubview:label];
[UIView animateWithDuration:0.2
animations:^ {
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:20];
[UIView setAnimationTransition:UIViewAnimationTransitionNone forView:self.view cache:YES];
label.frame = CGRectMake(-480, 0, 480, 21);
[UIView commitAnimations];
}
completion:^(BOOL finished) {
NSLog(#"Animation Done!");
if (array.count > 0)
{
nextIndex++;
NSString *strMessage = [array objectAtIndex:nextIndex];
[self marqueeMessage:strMessage];
}
}];
}
Some how, strings in array are being displayed in such a manner, that they are overlapping while performing animation.
Any idea, anyone???
Let me know, in case need more information.

Answer 1

-(void)viewDidLoad {
[super viewDidLoad];
array=[[NSArray alloc]initWithObjects:#"Scroll test",#"Scroll test1",#"Scroll test2",#"Scroll test3",#"Scroll test4",nil];
[self marqueeMessage:[array objectAtIndex:0]];
// Do any additional setup after loading the view, typically from a nib.
}
- (void)marqueeMessage:(NSString *)messageString {
label = [[UILabel alloc] initWithFrame:(CGRectMake(0, 50, 90, 21))];
//label.tag=nextIndex;
label.text = messageString;
[self.view addSubview:label];
[UIView beginAnimations:#"LBL" context:nil];
[UIView setAnimationDuration:3];
[UIView setAnimationDidStopSelector:#selector(performThis:)];
[UIView setAnimationDelegate:self];
label.frame = CGRectMake(360,50,90,21);
[UIView commitAnimations];
}
- (void) performThis:(id) sender {
if (i<[array count]) {
label.text = [array objectAtIndex:i];
i++;
}
else
{
i=0;
label.text = [array objectAtIndex:i];
}
label.frame = CGRectMake(-90,50,90,21);
[UIView beginAnimations:#"LBL" context:nil];
[UIView setAnimationDuration:3];
label.frame = CGRectMake(360,50,90,21);
[UIView setAnimationDelegate:self];
[UIView setAnimationDidStopSelector:#selector(performThis:)];
[UIView commitAnimations];
}
may help you.

Answer 2

I think you're never removing labels from superview... you need to keep reference to your label and do so :
[old_label removeFromSuperview];

Answer 3

It looks to me that your first animation (which lasts 0.2 seconds) finishes and the completion is called, which adds another label to your view, on top of the nested animation which lasts for 20 seconds and is therefore still on the screen, etc, etc. You'll end up with a pile of overlapping labels.