popToViewController&popToRootViewControllerAnimated后导航栏变nil

写项目遇到需要在支付成功页面直接返回到首页，支付成功页面需要隐藏导航栏，使用的是隐藏

- (void)viewWillAppear:(BOOL)animated{
    [super viewWillAppear:animated];
    self.navigationController.delegate = self;
}
- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated{
    BOOL isSelfVC = [viewController isKindOfClass:[self class]];
    [self.navigationController setNavigationBarHidden:isPageData animated:animated];
}

点击页面按钮返回到首页或者返回上一页使用方法

[self.navigationController popToRootViewControllerAnimated:YES];
[self.navigationController popToViewController:viewControler animated:YES];

执行后再到UINavigationControllerDelegate方法发现navigationController值为nil

WeWork Helper20191019110344.png

这样返回到指定页面后那个页面存在的导航栏会消失

解决办法：

在执行pop方法之前加上设置导航栏显示的代码

[self.navigationController setNavigationBarHidden:NO animated:NO];