Memory Issue when loading images in UITableviewcell? - ios

Question

I'm loading images from the server in UItableViewCell.
Since Each Image takes 10MB size It cause memory problem.
App crashes Whenever I do scroll over the tableView
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
locationcellObject=[self.tableView dequeueReusableCellWithIdentifier:#"cell" forIndexPath:indexPath];
NSDictionary *temp= [sortedArray objectAtIndex:indexPath.row];
locationcellObject.title.text=[temp objectForKey:#"locationtitle"];
locationcellObject.subtitle_Lbl.text=[temp objectForKey:#"category"];
NSString *trimmedtitle = [[temp objectForKey:#"locationtitle"]stringByReplacingOccurrencesOfString:#" " withString:#""];
NSString *name=[NSString stringWithFormat:#"images/%#.png",trimmedtitle];
NSString *imageName=[NSString stringWithFormat:#"http://my_URL_HERE/%#",name];
_tempData = [NSData dataWithContentsOfURL:[NSURL URLWithString:imageName]];
UIImage *display=[[UIImage alloc]initWithData:_tempData];
locationcellObject.locationPic_img_View.image=display;
locationcellObject.locationPic_img_View.contentMode=UIViewContentModeScaleAspectFit;
return locationcellObject;
}
Is there any Easy way to do it??

Answer 1

Download your images in background thread, download images with in the block. by this way two thread will be running in your app main thread and background thread. it will be reduces load on main thread.
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
//Call your function or whatever work that needs to be done
//Code in this part is run on a background thread
dispatch_async(dispatch_get_main_queue(), ^(void) {
//Stop your activity indicator or anything else with the GUI
//Code here is run on the main thread
});
});
And also add downloaded images in cache using NSCache,by which next time your images will be loaded from cache,
you can check this link here you can find how to add images in cache

Answer 2

Please refer THIS tutorial. It describes fetching/loading images in UItableView in efficient way.

Answer 3

1 ) you should do the downloading in the background
2 ) make a thumbnail of the image (image with smaller size)
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0),^ {
_tempData = [NSData dataWithContentsOfURL:[NSURL URLWithString:imageName]];
UIImage *display=[[UIImage alloc]initWithData:_tempData];
//make a thumbnail of the image
UIImage *display;
CGSize destinationSize = ...;
UIGraphicsBeginImageContext(destinationSize);
[originalImage drawInRect:CGRectMake(0,0,destinationSize.width,destinationSize.height)];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
//
dispatch_async(dispatch_get_main_queue(), ^{
//put result to main thread
locationcellObject.locationPic_img_View.image= newImage;
});
});