导航栏中的子菜单

<div class="navbar navbar-inverse navbar-fixed-top">
    <div class="container">
        <div class="navbar-header">
            <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-collapse">
                <span class="sr-only">Toggle navigation</span>
                <span class="icon-bar"></span>
                <span class="icon-bar"></span>
                <span class="icon-bar"></span>
            </button>
            <a class="navbar-brand" href="#">WebSite Title</a>
        </div>
        <div class="navbar-collapse collapse">
            <ul class="nav navbar-nav">
                <li><a href="#">Home</a></li>
                <li><a href="#">About">About</a></li>
                <li><a asp-controller="Home" asp-action="Contact">Contact</a></li>
                <!--- vvv Create a submenu in the navbar vvv --->
                <li class="dropdown">
                    <a href="#" class="dropdown-toggle" data-toggle="dropdown">Testing Stuff <b class="caret"></b></a>
                    <ul class="dropdown-menu">
                        <li><a href="#">SubItem</a></li>
                        <li><a href="#">Something Sub-y</a></li>
                    </ul>
                </li>
                <!--- ^^^ Create a submenu in the navbar ^^^ --->
            </ul>
        </div>
    </div>
</div>