topNav.php

 <!-- 顶部导航 -->
 <nav class="navbar navbar-inverse">
    <div class="container">
      <!-- Brand and toggle get grouped for better mobile display -->
      <div class="navbar-header">
        <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1"
          aria-expanded="false">
          <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="#">
          <span class="glyphicon glyphicon-phone-alt"></span>028-86261949</a>
      </div>

      <!-- 右边 -->
      <div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
        <ul class="nav navbar-nav navbar-right">
          <li id='homepage'>
            <a href="index.php">首页</a>
          </li>
          <li>
            <a href="#" data-toggle="tooltip" data-placement="bottom" data-html="true" title="<img src='./images/contract.png'>">联系客服</a>
          </li>
        </ul>
      </div>
      <!-- /.navbar-collapse -->
    </div>
    <!-- /.container-fluid -->
  </nav>

<!-- 引入query -->
<script src="./lib/jquery/jquery.min.js"></script>
<script>

    $.get("./api/checkState.php",function (data) {
      
        console.log(data)
        if(data.isSuccess){
          //显示登录后的菜单
          var htmlStr = ` <li>
            <a href="#">${data.username}</a>
          </li>
          <li>
            <a href="#">赶快充值</a>
          </li>
          <li>
            <a href="./api/loginOut.php">注销</a>
          </li>`;
          $("#homepage").after(htmlStr);
        }else{
          var htmlStr = ` <li>
            <a href="login.php">登录</a>
          </li>
          <li>
            <a href="register.php">注册</a>
          </li>
          <li>
            <a href="#">帮助</a>
          </li> `;
          $("#homepage").after(htmlStr);
        }
        
    },"json");




</script>