1.導航欄返回根視圖

[self.navigationController popToRootViewControllerAnimated:YES];

2.導航欄返回特定視圖

for (UIViewController *controller in self.navigationController.viewControllers) {
            if ([controller isKindOfClass:[要返回的類名 class]]) {
                [self.navigationController popToViewController:controller animated:YES];
            }
 }

3.dissmiss 返回根視圖

[self.presentingViewController.presentingViewController dismissViewControllerAnimated:NO completion:nil];