Main thread doesn't respond while NSOperationQueue is running its task

Question

I use NSOperationQueue to create UIImage s in the background,
upon image creation, main thread gets notified and set the image to a view.

While it works and all, main thread is not responding as I hoped while the NSOperationQueue is working.

The point of using thread here is to let UI be responsive to user interactions.
Am I missing something here?

Answer 1

check Invoking thread with a single parameter