Question

I am trying to add animation for UIImages which are added in an array. I would like to add animation to array index 0 and make it animated.I want to change the imageCount and animate it every 3 secs. I have also added NSTimer which will help me to change the image but it is not changing the image correctly. I have like a menu list in which the first link should be animated. Has anyone come across such an issue before and can help me out.

- (void)viewDidLoad {
[super viewDidLoad];
[NSTimer scheduledTimerWithTimeInterval:3 
                                 target:self 
                               selector:@selector(animateFunction) 
                               userInfo:nil 
                                repeats:YES];
[self setListArray:[NSMutableArray arrayWithObjects:@"",@"List",@"To-Do",nil]];

}

 -(void)animateFunction
   {
NSLog(@"Timer heartbeat %i",imageCount);
if (imageCount == 2) {
    // set the image count back to initial value;
    imageCount = 1;
} else {
    imageCount++;
}

[self setCellIconNames:[NSArray arrayWithObjects:[NSString stringWithFormat:@"image%i.png", imageCount],@"final.png",@"blue.png",nil]];
}



- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

static NSString *CellIdentifier = @"Cell";

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
    cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}

NSUInteger row = [indexPath row];


NSString *cellIconName = [[self cellIconNames] objectAtIndex:[indexPath row]];

UIImage *cellIcon = [UIImage imageNamed:cellIconName];
[[cell imageView] setImage:cellIcon];

cell.textLabel.text = [listArray objectAtIndex:row];
cell.backgroundColor = [UIColor clearColor];
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;

return cell;
}

Answer 1

I believe the problem is that imageCount is being set to 1 each time you call the method associated with the timer. Try declaring imageCount in the header file as something like int imageCount;, remove imageCount = 1; from the animateFunction method and place it in the viewDidLoad or some similar method to initialize it. Then when you iterate imageCount (which you can substitute imageCount = imageCount + 1 with just imageCount++ if you like), it will add 1 to the variable properly instead of returning 2 each time (which is what the current method does). If you need the images to loop, you will need to set up a check that resets the imageCount like the following:

if (imageCount == yourMaxNumber) {
    // set the image count back to initial value;
    imageCount = 1;
} else {
    imageCount++;
}

Hopefully that does the trick for you