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>')
@loginFirst
def usercenter(user_id,tag):
    user=User.query.filter(User.id == user_id).first()
    context={
        'username':user.username,
        'question':user.question,
        'comments':user.comments,
        'user':user
    }
    if tag =='1':
        return render_template("wenda.html",**context)
    elif tag =='2':
        return render_template('pinlun.html',**context)
    else:
        return render_template('usercenter3.html',**context)

<div class="page-header">
        <h5><span class="glyphicon glyphicon-user" aria-hidden="true"></span>☆{{ username }}☆<br><small>个人信息<span class="badge>"></span> </small> </h5>
        <ul class="list-group" style="margin:auto">
            <li class="list-group-item">用户：{{ username }}</li>
            <li class="list-group-item">编号：{{ user_id }}</li>
            <li class="list-group-item">评论次数：{{ comments|length }}</li>
        </ul>
    </div>