为什么我的 React 路由器只加载默认路由？答案

【问题标题】：Why my React router only loads the default route?为什么我的 React 路由器只加载默认路由？
【发布时间】：2019-03-11 09:28:04
【问题描述】：

我正在使用 react-router 在 React 应用程序中学习页面导航，

这是我的 package.json

{
  "name": "tutorial",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "start": "webpack-dev-server --inline --content-base .",
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "Rahul Shivsharan",
  "license": "ISC",
  "dependencies": {
    "react": "^16.8.4",
    "react-dom": "^16.8.4",
    "react-router": "^4.3.1",
    "react-router-dom": "^4.3.1"
  },
  "devDependencies": {
    "@babel/cli": "^7.2.3",
    "@babel/core": "^7.3.4",
    "@babel/plugin-proposal-class-properties": "^7.3.4",
    "@babel/preset-env": "^7.3.4",
    "@babel/preset-react": "^7.0.0",
    "babel-loader": "^8.0.5",
    "http-server": "^0.11.1",
    "webpack": "^4.29.6",
    "webpack-cli": "^3.2.3",
    "webpack-dev-server": "^3.2.1"
  }
}

这是我的 App.js

import React from "react";
import {Link} from "react-router";

export default class App extends React.Component{
    render(){
        return <div>Hello, React Router !!</div>
    }
}

这是 Repos.js

import React from "react"

export default class Repos extends React.Component{
    render(){
        return <div>Repos rendered !!!</div>
    }
}

这是 About.js

import React from "react"

export default class About extends React.Component{
    render(){
        return <div>About to be !!</div>
    }
}

这是 index.js

import React from "react";
import ReactDOM from "react-dom";
import {BrowserRouter,Route, Switch} from "react-router-dom";  
import App from "./modules/App";
import Repos from "./modules/Repos";
import About from "./modules/About";

ReactDOM.render(
    (<BrowserRouter>
        <Switch>            
            <Route path="/" component={App} />
            <Route path="/repos" component={Repos} />
            <Route path="/about" component={About} />       
        </Switch>
    </BrowserRouter>),  document.getElementById("app"));

这是我的 index.html

<!DOCTYPE html public "storage">
<html>
    <head>
        <meta charset="UTF-8">
        <title>My First React Router App</title>
    </head>
    <body>
        <div id="app"></div>
        <script src="./bundle.js"></script>
    </body> 
</html>

这是我的 webpack.config.js

module.exports = {
    "entry" : "./index.js",
    "output" : {
        "filename" : "bundle.js",
        "publicPath" : ""
    },
    "module" : {
        "rules" : [{
            "test" : /\.js$/,
            "exclude" : /node_modules/,
            "loader" : "babel-loader",
            "query": {
                "presets": ['@babel/react', '@babel/preset-env'],
                "plugins": ['@babel/proposal-class-properties']
            }
        }]
    }
}

我的问题是当我使用启动服务器时

npm start

并加载 http://localhost:8081

在浏览器中加载你好，反应路由器！

当我这样做时 http://localhost:8081/about

它表明，无法获取/关于

与 http://locahost:8081/repos

加载无法获取 /repos

为什么我无法加载默认路径以外的路径？

请帮帮我，是否我做错了什么，

【问题讨论】：

标签： javascript reactjs react-router react-router-v4 react-router-dom

【解决方案1】：

您需要启用 historyApiFallback 以便 webpack-dev-server 将为当前提供 404 Not Found 响应的所有路由提供 index.html 文件。

webpack.config.js

module.exports = {
  entry: "./index.js",
  output: {
    filename: "bundle.js",
    publicPath: ""
  },
  devServer: {
    historyApiFallback: true
  },
  module: {
    rules: [
      {
        test: /\.js$/,
        exclude: /node_modules/,
        loader: "babel-loader",
        query: {
          presets: ["@babel/react", "@babel/preset-env"],
          plugins: ["@babel/proposal-class-properties"]
        }
      }
    ]
  }
};

【讨论】：

但这并不能解决我的问题，我仍然无法在 url 或 /about 和 /repos 上呈现用 About.js 和 Repos.js 编写的 html

【解决方案2】：

我能够解决我的问题，

我只需要在我的 index.js 中做一些更改，如下所示，

import React from "react";
import ReactDOM from "react-dom";
import {BrowserRouter,Route, Switch} from "react-router-dom";  
import App from "./modules/App";
import Repos from "./modules/Repos";
import About from "./modules/About";

ReactDOM.render(
    (<BrowserRouter>
        <Switch>            
            <Route  exact path="/" component={App} />
            <Route  exact path="/repos" component={Repos} />
            <Route  exact path="/about" component={About} />        
        </Switch>
    </BrowserRouter>),  document.getElementById("app"));

上面你可以看到我在Route标签中添加了“exact”这个词

其次，正如 Thole 上述回答所建议的那样，我在 webpack.config.js 中添加了一个额外的配置，即如下所示，

"devServer": {
        "historyApiFallback": true
 }

就是这样，现在上面的例子可以工作了，

现在，

当我加载 http://locahost:8080

我加载在 App.js 中返回的 html

开启 http://localhost:8080/about

它加载在 About.js 中返回的 html 等等

【讨论】：