How to use Lazy Loading in Paging?

Question

I have a viewController, in that i have used Page control. and each page have 4 imageViews.

I have passed Xml and according to number of images in that i got the number of pages of pageControl that is (NumberOfImages/4).

I have done my code like this...

first i get url of each images and store them in Array..

for(int i=0;i<[Array Count];i++)
{
imgString=[NSString stringWithFormat:@"%@",[Array objectAtIndex:i]];
NSLog(@"string :%@",imgString);
NSString *abc=[imgString tringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
//NSLog(@"abc :%@",abc);

NSURL *url=[NSURL URLWithString:abc];
NSLog(@"url :%@",url);

NSData *data = [NSData dataWithContentsOfURL:url];

[ImageArray addObject:[UIImage ImageWithData:data]];
}

The above code takes time to fetch images from URL.and until all r not fetched i have to wait..

So i want to use Lazy Loading Here..I have show apple Lazy Loading Example for TableView..but not getting how to use it with Paging??

so can anyone suggest me what can i do for this?? any Help is appreciated..

score 0 · Accepted Answer · answered Jul 14 '11 at 10:53

You could create a Category for the UIImageView class and add some methods that will allow you to do the following:

Load the image from a cache file in the tmp directory - if a cache file can't be found, download the image from the web on a background thread then save it to cache.

By checking for a cache file first you can skip re-downloading the content.

By downloading the image on a background thread your application will not lag while waiting for content to finish loading.

By using a Category, your methods will apply to any UIImageView you want to use - and will even work in paging.

Rather than post a complete code solution here I'm going to suggest that you research and develop your own solution.

Best of luck.

Thanx cdo..I have already done exactly that you said..i download the images in background thread so my application UI do not block while fetching Images...i have done that.. By d way thanx for reply..i appreciate..:) — Nignesh, Jul 15 '11 at 05:05

How to use Lazy Loading in Paging?

1 Answers1