如果设置topBar的visible为false的时候，侧滑返回时无效的，可以通过修改原生里面ReactNativeNavigation.xcodeproj里的
UINavigationController+RNNOptions.m

//- (void)rnn_setNavigationBarVisible:(BOOL)visible animated:(BOOL)animated {
// [self setNavigationBarHidden:!visible animated:animated];
//}

• (void)rnn_setNavigationBarVisible:(BOOL)visible animated:(BOOL)animated {
  [self setNavigationBarHidden:!visible animated:animated];

  // enable slide-back
  if ([self.navigationController respondsToSelector:@selector(interactivePopGestureRecognizer)]) {
  self.interactivePopGestureRecognizer.enabled = YES;
  self.interactivePopGestureRecognizer.delegate = nil;
  }
  }

来实现侧滑返回