问题
In my iOS app, I am using NSTime to invoke a method which takes screenshot of the device screen. I am taking 30 screenshots per second. On simulator its working fine (as the processor of Mac is far more powerful than iPad). But it takes less number of screenshots in actual device. How can I do this? Any reliable alternative for timer? Please help
来源：https://stackoverflow.com/questions/16982374/how-to-take-30-screenshots-in-a-second-in-an-ios-device