两次React组件渲染

时间:2018-12-29 07:28:59

标签: javascript reactjs

因此,正如标题所述,由于某种原因,我的应用程序主页呈现了两次,但我不确定为什么。首先,我从BrowserRouter调用一个JS文件,然后从该位置调用HomePage组件和React Router,但随后我的页面呈现两次,我不确定为什么。

我的浏览器路由器(index.js):

 import React from 'react'
 import { render } from 'react-dom'
 import { BrowserRouter } from 'react-router-dom'
 import App from './App';


render((
    <BrowserRouter>
         <App />
    </BrowserRouter>
), document.getElementById('root'));

然后将App.js称为:

const App = () => (
    <div>
        <HomePage />
        <Route />
    </div>
)

export default App;

然后是我的主页组件(index.jsx):

import React from 'react';
import { Link } from 'react-router-dom';

    const HomePage = () => (
            <html>
            <ul><li>Home</li>
                <Link to='/projects'><li>Projects</li></Link>
                <li>Future Work</li>
                <li>About Me</li>
            </ul>
            <title>A Peak Into My Life</title>
            <h2>New Production Build</h2>
            <body>
            Projects Will Be Shown Here:


            <body> This is the Flinder application: </body>

            </html>
    )

export default HomePage;

和Route.js:

const Routes = () => (
    <main>
    <Switch>
        <Route exact path='/' component={HomePage}/>
        <Route exact path='/projects' component={Projects}/>
    </Switch>
    </main>
)

但是随后我的页面呈现如下:

enter image description here

我真的很困惑,所以任何建议都会有所帮助!我猜可能有问题,因为我在路由中调用的是jsx文件而不是js文件?

1 个答案:

答案 0 :(得分:4)

之所以发生这种情况,是因为您要渲染两次,一次是在App的顶层,一次是在Route组件中(当您访问/时)。

const App = () => (
    <div>
        <HomePage /> {/* you are rendering it here */}
        <Route />    {/* you are also rendering HomePage within Route */}
    </div>
)

您需要决定只在访问HomePage时显示/,还是无论访问哪条路线都始终显示它。

对于前者,您应该从HomePage中删除App

const App = () => (
    <div>
        <Route />    {/* only render HomePage within Route, when / is visited */}
    </div>
)

对于后者,您应该从HomePage中删除Route

const Routes = () => (
    <main>
    <Switch>
        <Route exact path='/' component={() => 'Welcome to the home page'}/>
        <Route exact path='/projects' component={Projects}/>
    </Switch>
    </main>
)