How to write a sort operation that can handle back event in navigationconroller?

How can I write a sort operation or another operation that doesn't stop to handle my touch events? For example, when I touch Back in UINavigationController, the app immediately goes back and releases the UIViewController.

Answers

Just put your sort operation into the background:

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_LOW, 0), ^(void) {
 // you sort operation here

     dispatch_async(dispatch_get_main_queue(), ^(void) {
         // you updated UI operation here
     });
});

Then you can release other code, but be careful to touch something outside

Need Your Help