To prevent multiple presenting controllers, you can use dismissModalViewControllerAnimated to fall back to the previous controller.
The principle is that self dismissModalViewControllerAnimated corresponds to presentModalViewController, and whoever presents, dismiss will return to whoever.
If dismiss fails, it is possible to call the jump of push. At this time, use pop: self . navigationController popViewControllerAnimate corresponding to pushViewController display
reference:
http://blog.csdn.net/xiaohei5188/article/details/9142015