ios动画从延迟开始

Question

just wanted to clear one thing, in iOS animations start in thread but before starting it, does it waits for main UI thread to be finish.Once animation started then u can do anything in main thread at same time.

[UIView transitionFromView:currentVisible
                                toView:reuseablView
                              duration:0.6
                               options:(UIViewAnimationOptionTransitionCurlUp|UIViewAnimationOptionShowHideTransitionViews)            
                            completion:^(BOOL finished) {
                                }
                            }];

[self callFunction1];

Here, animation starts with very little delay I think it waits for functioin1 call.

Any,Idea?

Answer 1

When you call [self callFunction1] , you're blocking the main thread so any animation is going to stop (or in this instance, not start yet). If it's a long running method you should move it to another thread.

Answer 2

The animation should be started on the main thread although it actually gets executed on a higher thread than what your app accesses so it can still perform while blocking because of how the core animation rendering server works. Make sure you at not calling this from some network code while. It on the main thread. If the second method is blocking the animation probably will proceed but the app and touch events would not work while being blocked. If the second method blocks long enough the delay on the animation could cause it not to fire on time. But once started the animation should be good to go even with the next method blocking. I recommend you don't block the main thread though. If you want that method to be called after the animation it should be in the completion block.

Finally to prove this you can call the animation first and then call sleep. Your app would be unresponsive but the animation would continue.