我们正在创建一个 POS 餐厅系统，我们希望调整设计，以便我们可以同时测试系统的外观和感觉。
我们正在使用 Asp.net 核心，我们已经从 github 尝试了这个存储库来尝试一些功能。
</head>
<body>
<header>
<nav class="navbar navbar-inverse navbar-fixed-top box-shadow mb-3">
<div class="container">
<div class="navbar-header">
<a class="navbar-brand" asp-area="" asp-controller="Home"
asp-action="Index">POS Title</a>
<button class="navbar-toggler" type="button" data-
toggle="collapse" data-target=".navbar-collapse" aria-
controls="navbarSupportedContent"
aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
</div>
<partial name="_LoginPartial" />
</nav>
<div id="wrapper" class="toggled"></div>
<div id="sidebar-wrapper"></div>
<ul class="sidebar-nav"style="margin-top:15px;">
<li class="nav-item">
<a class="nav-link text-dark" asp-area="" asp-
controller="Customer" asp-action="Index">Guest</a>
</li>
<li class="nav-item">
<a class="nav-link text-dark" asp-area="" asp-
controller="Vendor" asp-action="Index">Supplier</a>
</li>
<li class="nav-item">
<a class="nav-link text-dark" asp-area="" asp-
controller="Product" asp-action="Index">Menu</a>
</li>
<li class="nav-item">
<a class="nav-link text-dark" asp-area="" asp-
controller="PurchaseOrder" asp-action="Index">Purchases</a>
</li>
<li class="nav-item">
<a class="nav-link text-dark" asp-area="" asp-
controller="GoodsReceive" asp-action="Index">Goods Received</a>
</li>
<li class="nav-item">
<a class="nav-link text-dark" asp-area="" asp-
controller="SalesOrder" asp-action="Index">Sales Order</a>
</li>
<li class="nav-item">
<a class="nav-link text-dark" asp-area="" asp-
controller="SalesOrder" asp-action="POS">Point Of Sales</a>
</li>
<li class="nav-item">
<a class="nav-link text-dark" asp-area="" asp-
controller="InvenTran" asp-action="Index">Inventory</a>
</li>
</ul>
</div>
</div>
</nav>
</header>
<div id="page-content-wrapper">
<div class="container-fluid">
<partial name="_CookieConsentPartial" />
<main role="main" class="pb-3">
@RenderBody()
</main>
</div>
</div>
<footer class="border-top footer text-muted">
<div class="container">
© 2019 - POS Title - <a asp-area="" asp-controller="Home"
asp-action="Privacy">Privacy Policy</a>
</div>
</footer>
<environment include="Development">
<script src="~/lib/jquery/dist/jquery.js"></script>
<script src="~/lib/bootstrap/dist/js/bootstrap.bundle.js"></script>
</environment>
<environment exclude="Development">
<script
src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"
asp-fallback-src="~/lib/jquery/dist/jquery.min.js"
asp-fallback-test="window.jQuery"
crossorigin="anonymous"
integrity="sha256-
FgpCb/KJQlLNfOu91ta32o/NMZxltwRo8QtmkMRdAu8=">
</script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/twitter-
bootstrap/4.1.3/js/bootstrap.bundle.min.js"
asp-fallback-
src="~/lib/bootstrap/dist/js/bootstrap.bundle.min.js"
asp-fallback-test="window.jQuery && window.jQuery.fn &&
window.jQuery.fn.modal"
crossorigin="anonymous"
integrity="sha256-
E/V4cWE4qvAeO5MOhjtGtqDzPndRO1LBk8lJ/PR7CA4=">
</script>
</environment>
<!--datatables.net-->
<script src="~/lib/DataTables/datatables.min.js"></script>
<!--datatables.net-->
<!--axios-->
<script src="~/lib/axios/axios.min.js"></script>
<!--axios-->
<!--jquery numpad-->
<script src="~/lib/jquery-numpad/jquery.numpad.js"></script>
<!--jquery numpad-->
<!--toastr-->
<script src="~/lib/toastr/toastr.min.js"></script>
<!--toastr-->
<script src="~/js/site.js" asp-append-version="true"></script>
@RenderSection("Scripts", required: false)
</body>
</html>
所以，应该是这样，Customer、Vendor、Product、PurchaseOrder、GoodsReceived 等的导航应该在左侧，当你点击它们时，内容将显示在中心，菜单也应该留在并且在您导航到其他菜单时可见。请帮忙。