Loading images in background to optimize the loading in ios

Question

I am trying to optimize the load in my application, in fact, I have a lot of images that loaded in my application, and I spend a lot of time waiting for a view controller to ope

Answer 1

you can check this tutorial on NSOperationQueue and this on GCD doing exactly same. Also you can try using:

// Block variable to be assigned in block.
__block NSData *imageData;
dispatch_queue_t backgroundQueue  = dispatch_queue_create("com.razeware.imagegrabber.bgqueue", NULL);

// Dispatch a background thread for download
dispatch_async(backgroundQueue, ^(void) {
    imageData = [NSData dataWithContentsOfURL:imageURL];
    UIImage *imageLoad;
    imageLoad = [[UIImage alloc] initWithData:imageData];

    // Update UI on main thread
    dispatch_async(dispatch_get_main_queue(), ^(void) {
        imageView.image = imageLoad;
    });
});