iOS thread problem

I load image by NSOparationInvokation and call out method in the main thread, which adds this image to scroll view, but app hardly lags. If I load image but not add it view,开发者_如何学JAVA app works normally, if I add test button on view app also work normally and if I load image and add test button to view app don't lag. By profiler problem in __spin_lock. Someone knows what's wrong? Thanks.

When using threads on iOS, you should never ever ever make calls to UIKit. That's why it won't load. Put it on the main thread and it'll work.