html - 如何使侧边栏在增加宽度时不显示？

Question

示例页面是http://blackrockdigital.github.io/startbootstrap-simple-sidebar/

第一次打开页面时，有侧边栏和主要内容。

并且当你减小浏览器的宽度时，侧边栏会消失，当你稍后增加宽度时，侧边栏会再次出现。哪个好。

但如果您打开该页面，请先点击“切换菜单”关闭侧边栏。

然后如果你减少浏览器的宽度，侧边栏就会显示出来!如何让它不显示？

然后如果你以后增加宽度，侧边栏就会消失!如何让它仍然显示？

#wrapper {
    padding-left: 0;
    -webkit-transition: all 0.5s ease;
    -moz-transition: all 0.5s ease;
    -o-transition: all 0.5s ease;
    transition: all 0.5s ease;
}

#wrapper.toggled {
    padding-left: 250px;
}

#sidebar-wrapper {
    z-index: 1000;
    position: fixed;
    left: 250px;
    width: 0;
    height: 100%;
    margin-left: -250px;
    overflow-y: auto;
    background: #000;
    -webkit-transition: all 0.5s ease;
    -moz-transition: all 0.5s ease;
    -o-transition: all 0.5s ease;
    transition: all 0.5s ease;
}

#wrapper.toggled #sidebar-wrapper {
    width: 250px;
}

#page-content-wrapper {
    width: 100%;
    position: absolute;
    padding: 15px;
}

#wrapper.toggled #page-content-wrapper {
    position: absolute;
    margin-right: -250px;
}

/* Sidebar Styles */

.sidebar-nav {
    position: absolute;
    top: 0;
    width: 250px;
    margin: 0;
    padding: 0;
    list-style: none;
}

.sidebar-nav li {
    text-indent: 20px;
    line-height: 40px;
}

.sidebar-nav li a {
    display: block;
    text-decoration: none;
    color: #999999;
}

.sidebar-nav li a:hover {
    text-decoration: none;
    color: #fff;
    background: rgba(255,255,255,0.2);
}

.sidebar-nav li a:active,
.sidebar-nav li a:focus {
    text-decoration: none;
}

.sidebar-nav > .sidebar-brand {
    height: 65px;
    font-size: 18px;
    line-height: 60px;
}

.sidebar-nav > .sidebar-brand a {
    color: #999999;
}

.sidebar-nav > .sidebar-brand a:hover {
    color: #fff;
    background: none;
}

@media(min-width:768px) {
    #wrapper {
        padding-left: 250px;
    }

    #wrapper.toggled {
        padding-left: 0;
    }

    #sidebar-wrapper {
        width: 250px;
    }

    #wrapper.toggled #sidebar-wrapper {
        width: 0;
    }

    #page-content-wrapper {
        padding: 20px;
        position: relative;
    }

    #wrapper.toggled #page-content-wrapper {
        position: relative;
        margin-right: 0;
    }
}

<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.0/jquery.min.js"></script>
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css" rel="stylesheet"/>
 <div id="wrapper">

        <!-- Sidebar -->
        <div id="sidebar-wrapper">
            <ul class="sidebar-nav">
                <li class="sidebar-brand">
                    <a href="#">
                        Start Bootstrap
                    </a>
                </li>
                <li>
                    <a href="#">Dashboard</a>
                </li>
                <li>
                    <a href="#">Shortcuts</a>
                </li>
                <li>
                    <a href="#">Overview</a>
                </li>
                <li>
                    <a href="#">Events</a>
                </li>
                <li>
                    <a href="#">About</a>
                </li>
                <li>
                    <a href="#">Services</a>
                </li>
                <li>
                    <a href="#">Contact</a>
                </li>
            </ul>
        </div>
        <!-- /#sidebar-wrapper -->

        <!-- Page Content -->
        <div id="page-content-wrapper">
            <div class="container-fluid">
                <div class="row">
                    <div class="col-lg-12">
                        <h1>Simple Sidebar</h1>
                        <p>This template has a responsive menu toggling system. The menu will appear collapsed on smaller screens, and will appear non-collapsed on larger screens. When toggled using the button below, the menu will appear/disappear. On small screens, the page content will be pushed off canvas.</p>
                        <p>Make sure to keep all page content within the <code>#page-content-wrapper</code>.</p>
                        <a href="#menu-toggle" class="btn btn-default" id="menu-toggle">Toggle Menu</a>
                    </div>
                </div>
            </div>
        </div>
        <!-- /#page-content-wrapper -->

    </div>
    <!-- /#wrapper -->

    <!-- jQuery -->
    <script src="js/jquery.js"></script>

    <!-- Bootstrap Core JavaScript -->
    <script src="js/bootstrap.min.js"></script>

    <!-- Menu Toggle Script -->
    <script>
    $("#menu-toggle").click(function(e) {
        e.preventDefault();
        $("#wrapper").toggleClass("toggled");
    });
    </script>

Answer 1

下面的 javascript 应该可以解决问题:

  $(window).resize(function() {
      var viewportW = $(window).width();
      if(viewportW < 768 ) {
        $('#wrapper').removeClass('toggled')
      }
    });

这可确保当视口(viewport)低于 768 时删除“切换”类。

虽然在调整浏览器大小时看到这种效果很不错，但请记住，用户永远不会真正这样做。在正常用例中，用户在特定视口(viewport)中打开 UI 并坚持使用它。