my imageviews are not behaving properly in the table view? - iphone

Question

I have a table view loading in the below manner. If a condition is met I need to add a particular image above the cell.imageview. Also the images are coming in different dimensions. Below is my code can anybody point me in where i am going wrong.
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier] autorelease];
}
if(array==nil||[array count]==0)
{
}
else
{
NSMutableDictionary *dicttable=[array objectAtIndex:indexPath.row];
NSString *head=[dicttable objectForKey:#"name"];
NSString *type=[dicttable objectForKey:#"type"];
NSString *imgUrl = [dicttable objectForKey:#"image"];;
if(imgUrl!=nil)
{
if(![[ImageCache sharedImageCache] hasImageWithKey:imgUrl])
{
cell.imageView.image = [UIImage imageNamed:#"noimage_icon.png"];
NSArray *myArray = [NSArray arrayWithObjects:cell.imageView,imgUrl,#"noimage_icon.png",[NSNumber numberWithBool:NO],nil];
AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
[appDelegate performSelectorInBackground:#selector(updateImageViewInBackground:) withObject:myArray];
cell.imageView.frame=CGRectMake(0,0,48,48);
cell.imageView.bounds=CGRectMake(0,0,48,48);
[cell.imageView setClipsToBounds:NO];
}
else
{
cell.imageView.image = [[ImageCache sharedImageCache] getImagefromCacheOrUrl:imgUrl];
cell.imageView.frame=CGRectMake(0,0,48,48);
cell.imageView.bounds=CGRectMake(0,0,48,48);
[cell.imageView setClipsToBounds:NO];
}
}
else
{
cell.imageView.image = [UIImage imageNamed:#"noimage_icon.png"];
}
if([type isEqualToString:#"YES"])
{
UIImageView* img = [[UIImageView alloc]initWithImage:[UIImage imageNamed:#"bluel.png"]];
[cell setBackgroundView:img];
[img release];
cell.textLabel.text = head;
cell.textLabel.backgroundColor = [UIColor clearColor];
cell.detailTextLabel.textColor=[UIColor grayColor];
cell.detailTextLabel.text = subtitle1;
cell.detailTextLabel.backgroundColor = [UIColor clearColor];
}
else
{
UIImageView* img = [[UIImageView alloc]initWithImage:[UIImage imageNamed:#"wnew1.png"]];
[cell setBackgroundView:img];
[img release];
cell.textLabel.text = head;
cell.textLabel.backgroundColor = [UIColor clearColor];
[cell.imageView addsubview:spclimage]
cell.textLabel.text = head;
cell.textLabel.backgroundColor = [UIColor clearColor];
cell.detailTextLabel.textColor=[UIColor grayColor];
cell.detailTextLabel.text = subtitle1;
cell.detailTextLabel.backgroundColor = [UIColor clearColor];
}
}
return cell;
Here the problem is only in the last row the special image is adding. Not in all rows. Also the image view size is different in all the time the tableview is reloading?

Answer 1

A couple of thoughts:
The updateImageViewInBackground seems suspect, as the name suggests that you're updating an image view, but you don't specify which cell you're updating.
I also see you doing a addSubview:spclimage. Obviously, if that spclimage was on another cell, as soon as you do addSubview, it will be removed from the previous location before being added to current cell. In fact, just the notion of adding an image as a subview of an existing imageview is curious.
If your cache doesn't have the image yet, I see where you're initializing the image with noimage_icon.png, but I don't see where you're actually updating the image view. You say updateImageViewInBackground is "then updating the image". Do you mean setting the image property for the imageView for this cell for this indexPath? Or maybe updating spclimage? If so, that's problematic.
The typical pattern (using GCD) for this would be:
cell.imageView.image = [UIImage imageNamed:#"noimage_icon.png"];
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
UIImage *image = ... // do whatever you need to do to get the image, load cache, etc.
// ok, now that you have the image, dispatch the update of the UI back to the main queue
dispatch_async(dispatch_get_main_queue(), ^{
// because we're doing this asynchronously, make sure the cell is still
// visible (it could have scrolled off and the cell was dequeued and
// reused), so we're going to ask the tableview for the cell for that
// indexPath, and it returns `nil` if it's not visible. This method is
// not to be confused with the similarly named `UITableViewControllerDelegate`
// method.
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
// if the image view is still visible, update it
if (cell)
{
cell.imageView.image = image;
}
});
});