<i class="header-help-icon down" ng-class="{up:showMenu}"></i> 

<i className={"header-help-icon down" + (this.state.isShowLoginMenu ? ' up' : '')}></i> 

 
<span id="vip-header-logo" className={'vip-logo icon-vip-v' + this.state.vipLevel}></span> 

<div class="logined" ng-show="isLogin">登录了</div> 
<div class="logined" ng-if="isLogin">你好，{userName}</div> 
<div class="no-login" ng-hide="isLogin">未登录</div> 

React.createClass({ 
 getInitialState: function() { 
  return { 
   isLogin: true, 
   userName: 'Joe' 
  }; 
 }, 
 
 render: function() { 
   var isLogin = this.state.isShowLoginMenu, 
   loginHtml; 
 
   if (isLogin) { 
    loginHtml = 
     <div className="logined"> 
      登录了，欢迎{this.state.userName} 
     </div>; 
   } else { 
    loginHtml = 
     <div className="no-login"> 
      未登录 
     </div>; 
   } 
 
  return ( 
    <div className="user"> 
     {loginHtml} 
    </div> 
  ); 
 }