A UINavigationController's category to enable fullscreen pop gesture with iOS7+ system style.
网址：https://github.com/forkingdog/FDFullscreenPopGesture
pod 'FDFullscreenPopGesture', '1.1'
使用此弹出姿态的导航控制器navigationController：
navigationController.fd_fullscreenPopGestureRecognizer.enabled = YES;
使用此弹出姿态的控制器viewController：
viewController.fd_interactivePopDisabled = YES;
如图所示：
demo
