2019-07-31 导航或覆盖返回时pop 还是 dis 自动

-(void)fanhui{
    NSArray *viewControllers = self.navigationController.viewControllers;
    if (viewControllers.count > 1) {
        if ([viewControllers objectAtIndex:viewControllers.count - 1] == self) {
            //push方式
            [self.navigationController popViewControllerAnimated:YES];
        }
    }else{
        //present方式
        [self dismissViewControllerAnimated:NO completion:nil];
    }
}