Router 代码：

import React from 'react';
import { Router, Route, hashHistory , IndexRoute} from 'react-router';
import Layout from '../components/layout/layout.jsx';
import Index from '../components/index.jsx';


export default class extends React.Component {
    render(){
        return (
              
                
                    
                
              
            );
    }
};

Layout代码：

import React from 'react';
import {Layout,Affix,BackTop,Icon} from 'antd';
const {Header,Content,Footer}  = Layout;
import LayoutFooter from './footer.jsx';
import LayoutHeader from './header.jsx';


require("./style/layout.less");

export default class CnodeLayout extends React.Component {
    static visibilityHeight = window.innerHeight + 100;
    render(){
        console.log('Layout render called');
        return (
            
                
                    
                
                

                    {this.props.children}
                
                
                
                    
                
            
            );
    }
}

链接的代码：

class NavTag extends React.Component {
    render(){
        return (
                

                    
                        全部
                    
                    
                        精华
                    
                    
                        分享
                    
                    
                        问答
                    
                    
                        招聘
                    
                
            );
    }
}

查看了一下渲染出来的dom,也是正确的：

这是我的打印信息，object 答应的是react-router 的location

但是我在Layout和Index中打印输出发现render 会被调用两次。。。请问是为什么？