bootstrap-4 - Bootstrap 4 导航栏垂直出现而不是水平出现

Question

我已经完全按照教程中的方式构建了一个导航栏，但不知何故，当它应该水平显示时，我的导航栏会垂直显示。关于如何解决这个问题的任何想法？提前致谢

<nav class="navbar navbar-fixed-top navbar-light bg-faded">
    <div class='container'>
        <ul class="nav navbar-nav">
            <li class='nav-item'>
                <a class='nav-link' routerLink="/home" routerLinkActive="active">Home</a>
            </li>
            <li class='nav-item'>
                <a class='nav-link' routerLink="/documents" routerLinkActive="active">Docs</a>
            </li>
            <li class="nav-item dropdown">
                <div ngbDropdown class="d-inline-block dropdown-links">
                    <button class="btn btn-outline-primary" id="proposalDropdown" ngbDropdownToggle>
                        Proposals
                    </button>
                    <div class="dropdown-menu" aria-labelledby="proposalDropdown">
                        <a class="dropdown-item" routerLink="/proposals" routerLinkActive="active" [routerLinkActiveOptions]="{ exact: true}">Proposals</a>
                        <a class="dropdown-item" routerLink="/proposals/new" routerLinkActive="active">New Proposal</a>
                    </div>
                </div>
            </li>
        </ul>
    </div>
</nav>

Answer 1

添加 navbar-toggleable-sm ( md/lg ) 到 nav元素使其水平直到 sm ，否则每次都会垂直渲染。

<nav class="navbar navbar-toggleable-sm navbar-fixed-top navbar-light bg-faded">

   ....

</nav>

Demo Plunker