如何使用dart自动关闭bootstrap3的导航栏崩溃？

Question

导航栏看起来像这样：

我已经搜索了关于jquery的答案，但我根本不知道jquery ...... html代码是：

<div class="navbar-header">
        <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#navbar" aria-expanded="false" aria-controls="navbar">
            <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="http://www.zhi-tech.com" target="_blank">SmartGas System</a>
    </div>
    <div id="navbar" class="nav-pills navbar-collapse collapse">
        <ul class="nav navbar-nav navbar-right">
            <li [class.active]="getLinkStyle('')">
                <a class="link" [routerLink]="['/Home']">系统总览</a>
            </li>
            <li class="dropdown">
                <a class="dropdown-toggle" data-toggle="dropdown" href="#" role="button" aria-haspopup="true" aria-expanded="false">
                    账户管理 <span class="caret"></span>
                </a>
                <ul class="dropdown-menu">
                    <li [class.active]="getLinkStyle('/account_managger/manual_meter')">
                        <a class="link" [routerLink]="['/AccountManualMeter']">人工账单</a>
                    </li>
                </ul>
            </li>
            <li [class.active]="getLinkStyle('/device_manager')">
                <a class="link" [routerLink]="['/DeviceManager']">设备管理</a>
            </li>
            <li class="disabled"><a>权限管理</a></li>
            <li class="disabled"><a>统计信息</a></li>
        </ul>
    </div>