我不知道我做错了什么，我想在页面滚动时更改导航栏的背景颜色

Question

This is what i am doing, I used bootstrap to style this nav. The nav basically collapses and a toggle button appears.

<nav id="mainNavbar" class="navbar navbar-expand-lg navbar-dark py-0 fixed-top ">
        <div class="container-fluid">
            <a class="navbar-brand" href="#">CANDY</a>

            <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarTogglerDemo01"
                aria-controls="navbarTogglerDemo01" aria-expanded="false" aria-label="Toggle navigation"
                class="btn btn-info">
                <span class="navbar-toggler-icon"></span>
            </button>
            <div class="collapse navbar-collapse" id="navbarTogglerDemo01">
                <ul class="navbar-nav ">
                    <li class="nav-item">
                        <a class="nav-link" href="#">HOME</a>
                    </li>
                    <li class="nav-item">
                        <a class="nav-link" href="#">ABOUT</a>
                    </li>
                    <li class="nav-item">
                        <a class="nav-link" href="#">TICKETS</a>
                    </li>
                </ul>
            </div>
    </nav>

this is the css for styling it when scrolled. Nothing else was used to style it

#mainNavbar.scrolled{
    background-color: #ac3bac;
    transition: background 500ms;
}

But the problem is that it isn't toggling the class 'scrolled' to style it. I have tried multiple approaches but none of them are working. If possible pls help me complete it

<script>enter code here
        $(function () {
            $(document).scroll(function () {
                var $nav = $("#mainNavbar");
                $nav.toggleClass("scrolled", $(this).scrollTop() > $nav.height());
            });
        });
    </script>

Answer 1

I just tried your code here , which i hope it will help you to focus on your problem.

I have add some lorem in order to make the window scroll properly, in order to trigger the event.

<div>lorem...</div>

Everything should work fine, are you sure have you add all the proper scripts?