How to load more images on Lazy Loading - iphone

Question

In mu UITable view,I am displaying images from server..For that I am using lazy loading.
I can load the images when the rows are on screen.How to increase the number of images loaded.
like- for the first time 3 table cells are visible,and the images on those cells get loaded with 2seconds delay.How can I load the images on next 3 rows at same time ?
I am using below function to load images
- (void)loadImagesForOnscreenRows
{
if ([imageArray count] > 0)
{
NSArray *visiblePaths = [tableView indexPathsForVisibleRows];
for (NSIndexPath *indexPath in visiblePaths)
{
AppRecord *appRecord = [dataArray objectAtIndex:indexPath.row];
if (!appRecord.appIcon) // avoiding the imagen download if already has an image
{
[self startIconDownload:appRecord forIndexPath:indexPath];
}
}
}
}

Answer 1

Your way to do things
You can do that by downloading images on background and when they do finish, you can post a NSNotification to a method to reload tableView. But while the images are being downloaded, you have to show a loading view or something to the user to tell him that images are being downloaded.
Suggestion
I don't recommend that to you, the best way is to download each of them in background independently with SDWebImage and also make a faster response of your tableView. While the image is being downloaded you show a default image (placeholder), after the image is being downloaded this function sets it where it needs to be:
SDWebImage
You just need to #import <SDWebImage/UIImageView+WebCache.h> to your project, and you can define also the placeholder when image is being downloaded with just this code:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier;
CustomCell *cell = [tableview dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
MyObject *object = (MyObject *)[self.list.array objectAtIndex:indexPath.row];
//Here is where you set your image URL and it's placeholder
[cell.imageView setImageWithURL:[NSURL URLWithString:#"http://www.domain.com/path/to/image.jpg"]
placeholderImage:[UIImage imageNamed:#"placeholder.png"]];
return cell;
}
It also cache downloaded images and gives you great performance.

Answer 2

Why are you using this code you can just change below key value and it is just work perfectly with un limited images.
kIDStr = #"id";
kNameStr = #"im:name";
kImageStr = #"im:image";
kArtistStr = #"im:artist";
kEntryStr = #"entry";