完成个人中心—导航标签

1. 个人中心—视图函数带标签页面参数tag
   @app.route('/usercenter/<user_id>/<tag>')
   def usercenter(user_id, tag):
      if tag == ‘1':
          return render_template('usercenter1.html', **context)
   
   
2. 个人中心—导航标签链接增加tag参数
   <li role=“presentation”><a href=“{{ url_for(‘usercenter’,user_id = user.id,tag = ‘1’) }}">全部问答</a></li>
   
   
3. 个人中心—有链接到个人中心页面的url增加tag参数
    <a href="{{ url_for('usercenter',user_id = session.get('userid'), tag=1) }}">{{ session.get('user') }}</a>

   @app.route('/usercenter/<user_id>/<tag>')
   @log
   def  usercenter(user_id,tag):
        user=User.query.filter(User.id==user_id).first()
        context={
           'username':user.username,
           'questions':user.question,
           'comments':user.comments
       }
        if tag =='1':
             return render_template('wenda.html',**context)
        elif tag =='2':
             return render_template('comment.html',**context)
        else :
             return render_template('grxx.html',**context)

   <ul class="nav_ul">
             <li role="presentation"><a href="{{ url_for('usercenter',user_id=user.id,tag='1') }}">Questions</a> </li>
             <li role="presentation"><a href="{{ url_for('usercenter',user_id=user.id,tag='2') }}">Comments</a> </li>
             <li role="presentation"><a href="{{ url_for('usercenter',user_id=user.id,tag='3') }}">Info</a> </li>
         </ul>

   detail.html
    <a href="{{ url_for('usercenter',user_id=ques.author_id,tag=1) }}">{{ ques.author.username }}</a>
   
   base.html
   <li><a href="{{ url_for('usercenter',user_id=session.get('user_id'),tag=1)}}">{{session.get('user')}}</a></li>
   
   index.html
    <li><a href="{{ url_for('usercenter',user_id=foo.author_id,tag=1)}}">{{foo.author.username }}</a></li>