iOS13以上导航栏状态栏黑色渐变问题解决

if (@available(iOS 13.0, *)) {
        UINavigationBarAppearance *appearance = [UINavigationBarAppearance new];
        [appearance configureWithOpaqueBackground];//重置导航栏背景颜色和阴影
        appearance.backgroundColor = [UIColor whiteColor];
//        appearance.shadowImage = [UIImage new];
//        appearance.shadowColor = nil;
        self.navigationController.navigationBar.standardAppearance = appearance;
        self.navigationController.navigationBar.scrollEdgeAppearance = appearance;
    }