转换为WordPress导航菜单

Question

我的html设计包含不同级别的不同css类。如何通过walker将其转换为WordPress navMenu？

<section class="nav-bg">
        <div class="container">
          <nav class="navbar" role="navigation"> 

            <div class="navbar-header">
              <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-ex1-collapse"> <span
    class="sr-only">Toggle navigation</span> <span
    class="icon-bar"></span> <span class="icon-bar"></span> <span
    class="icon-bar"></span> </button>
            </div>

            <!-- Collect the nav links, forms, and other content for toggling -->
            <div class="collapse navbar-collapse navbar-ex1-collapse">
              <!--<ul class="nav navbar-nav">
                <li role="presentation"><a href="<?php echo get_template_directory_uri();?>/index.php"
    class="active">Home</a></li>
                <li class="dropdown"> <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button"
    aria-expanded="false">company <span class="caret"></span></a>
                  <ul class="dropdown-menu" role="menu">
                    <li><a href="<?php echo get_template_directory_uri();?>/profile.php">company
    profile</a></li>
                    <li class="divider"></li>
                    <li><a href="#">something</a></li>