沒有組件在HTML頁面中可見，反應js

Question

我是一個初學者，我嘗試創建一個網頁，爲此，我在此鏈接之後創建了一個新的反應應用程序https://github.com/facebookincubator/create-react-app。

還安裝了的WebPack以下網址：

https://www.davidmeents.com/blog/journey-into-react-part-2-creating-your-first-react-app/

先裝反應

C:\Users\siddhi jambhale\Desktop\react-demo>npm install react --save 
my-app@0.1.0 C:\Users\siddhi jambhale\Desktop\react-demo 
`-- react@15.5.4 

然後安裝反應-演示

C:\Users\siddhi jambhale\Desktop\react-demo>npm install react-dom --save 
my-app@0.1.0 C:\Users\siddhi jambhale\Desktop\react-demo 
`-- react-dom@15.5.4 

然後創建webpack.config.js

var webpack = require('webpack'); 

module.exports = { 
    context: __dirname, 
    entry: "./src/index.js", 
    module: { 
     loaders: [ 
      { 
       test: /\.js|.jsx?$/, 
       exclude: /(node_modules|bower_components)/, 
       loader: 'babel-loader', 
       query: { 
        presets: ['react', 'es2015', 'stage-2'], 
        plugins: ['react-html-attrs', 'transform-class-properties', 
         'transform-decorators-legacy'] 
       } 
      } 
     ] 
    }, 
    output: { 
     path: __dirname, 
     filename: "bundle.js" 
    } 
}; 

然後安裝的WebPack我得到的輸出是這樣的：

C:\Users\siddhi jambhale\Desktop\react-demo>npm install webpack webpack-dev-server --save-dev 
my-app@0.1.0 C:\Users\siddhi jambhale\Desktop\react-demo 
+-- webpack@2.5.1 
| +-- acorn@5.0.3 
| +-- acorn-dynamic-import@2.0.2 
| | `-- acorn@4.0.11 
| +-- ajv@4.11.8 
| | +-- co@4.6.0 
| | `-- json-stable-stringify@1.0.1 
| | `-- jsonify@0.0.0 
| +-- ajv-keywords@1.5.1 
| +-- async@2.4.0 
| | `-- lodash@4.17.4 
| +-- enhanced-resolve@3.1.0 
| | `-- graceful-fs@4.1.11 
| +-- interpret@1.0.3 
| +-- json-loader@0.5.4 
| +-- json5@0.5.1 
| +-- loader-runner@2.3.0 
| +-- loader-utils@0.2.17 
| | +-- big.js@3.1.3 
| | `-- emojis-list@2.1.0 
| +-- memory-fs@0.4.1 
| | +-- errno@0.1.4 
| | | `-- prr@0.0.0 
| | `-- readable-stream@2.2.9 
| | +-- buffer-shims@1.0.0 
| | +-- core-util-is@1.0.2 
| | +-- isarray@1.0.0 
| | +-- process-nextick-args@1.0.7 
| | +-- string_decoder@1.0.0 
| | `-- util-deprecate@1.0.2 
| +-- mkdirp@0.5.1 
| | `-- minimist@0.0.8 
| +-- node-libs-browser@2.0.0 
| | +-- assert@1.4.1 
| | +-- browserify-zlib@0.1.4 
| | | `-- pako@0.2.9 
| | +-- buffer@4.9.1 
| | | +-- base64-js@1.2.0 
| | | `-- ieee754@1.1.8 
| | +-- console-browserify@1.1.0 
| | | `-- date-now@0.1.4 
| | +-- constants-browserify@1.0.0 
| | +-- crypto-browserify@3.11.0 
| | | +-- browserify-cipher@1.0.0 
| | | | +-- browserify-aes@1.0.6 
| | | | | `-- buffer-xor@1.0.3 
| | | | +-- browserify-des@1.0.0 
| | | | | `-- des.js@1.0.0 
| | | | `-- evp_bytestokey@1.0.0 
| | | +-- browserify-sign@4.0.4 
| | | | +-- bn.js@4.11.6 
| | | | +-- browserify-rsa@4.0.1 
| | | | +-- elliptic@6.4.0 
| | | | | +-- brorand@1.1.0 
| | | | | +-- hash.js@1.0.3 
| | | | | +-- hmac-drbg@1.0.1 
| | | | | `-- minimalistic-crypto-utils@1.0.1 
| | | | `-- parse-asn1@5.1.0 
| | | | `-- asn1.js@4.9.1 
| | | +-- create-ecdh@4.0.0 
| | | +-- create-hash@1.1.3 
| | | | +-- cipher-base@1.0.3 
| | | | +-- ripemd160@2.0.1 
| | | | | `-- hash-base@2.0.2 
| | | | `-- sha.js@2.4.8 
| | | +-- create-hmac@1.1.6 
| | | | `-- safe-buffer@5.0.1 
| | | +-- diffie-hellman@5.0.2 
| | | | `-- miller-rabin@4.0.0 
| | | +-- pbkdf2@3.0.12 
| | | +-- public-encrypt@4.0.0 
| | | `-- randombytes@2.0.3 
| | +-- domain-browser@1.1.7 
| | +-- events@1.1.1 
| | +-- https-browserify@0.0.1 
| | +-- os-browserify@0.2.1 
| | +-- path-browserify@0.0.0 
| | +-- process@0.11.10 
| | +-- punycode@1.4.1 
| | +-- querystring-es3@0.2.1 
| | +-- stream-browserify@2.0.1 
| | +-- stream-http@2.7.1 
| | | +-- builtin-status-codes@3.0.0 
| | | +-- to-arraybuffer@1.0.1 
| | | `-- xtend@4.0.1 
| | +-- string_decoder@0.10.31 
| | +-- timers-browserify@2.0.2 
| | +-- tty-browserify@0.0.0 
| | +-- url@0.11.0 
| | | +-- punycode@1.3.2 
| | | `-- querystring@0.2.0 
| | +-- util@0.10.3 
| | | `-- inherits@2.0.1 
| | `-- vm-browserify@0.0.4 
| | `-- indexof@0.0.1 
| +-- source-map@0.5.6 
| +-- supports-color@3.2.3 
| | `-- has-flag@1.0.0 
| +-- tapable@0.2.6 
| +-- uglify-js@2.8.23 
| | +-- uglify-to-browserify@1.0.2 
| | `-- yargs@3.10.0 
| | +-- camelcase@1.2.1 
| | +-- cliui@2.1.0 
| | | +-- center-align@0.1.3 
| | | | +-- align-text@0.1.4 
| | | | | +-- longest@1.0.1 
| | | | | `-- repeat-string@1.6.1 
| | | | `-- lazy-cache@1.0.4 
| | | +-- right-align@0.1.3 
| | | `-- wordwrap@0.0.2 
| | `-- window-size@0.1.0 
| +-- watchpack@1.3.1 
| +-- webpack-sources@0.2.3 
| | `-- source-list-map@1.1.2 
| `-- yargs@6.6.0 
| +-- camelcase@3.0.0 
| +-- cliui@3.2.0 
| | `-- wrap-ansi@2.1.0 
| +-- decamelize@1.2.0 
| +-- get-caller-file@1.0.2 
| +-- os-locale@1.4.0 
| | `-- lcid@1.0.0 
| | `-- invert-kv@1.0.0 
| +-- read-pkg-up@1.0.1 
| | +-- find-up@1.1.2 
| | | `-- path-exists@2.1.0 
| | `-- read-pkg@1.1.0 
| | +-- load-json-file@1.1.0 
| | | +-- parse-json@2.2.0 
| | | | `-- error-ex@1.3.1 
| | | | `-- is-arrayish@0.2.1 
| | | +-- pify@2.3.0 
| | | `-- strip-bom@2.0.0 
| | | `-- is-utf8@0.2.1 
| | +-- normalize-package-data@2.3.8 
| | | +-- hosted-git-info@2.4.2 
| | | +-- is-builtin-module@1.0.0 
| | | | `-- builtin-modules@1.1.1 
| | | +-- semver@5.3.0 
| | | `-- validate-npm-package-license@3.0.1 
| | | +-- spdx-correct@1.0.2 
| | | | `-- spdx-license-ids@1.2.2 
| | | `-- spdx-expression-parse@1.0.4 
| | `-- path-type@1.1.0 
| +-- require-directory@2.1.1 
| +-- require-main-filename@1.0.1 
| +-- set-blocking@2.0.0 
| +-- string-width@1.0.2 
| | +-- code-point-at@1.1.0 
| | `-- is-fullwidth-code-point@1.0.0 
| | `-- number-is-nan@1.0.1 
| +-- which-module@1.0.0 
| +-- y18n@3.2.1 
| `-- yargs-parser@4.2.1 
|  `-- camelcase@3.0.0 
`-- webpack-dev-server@2.4.5 
    +-- ansi-html@0.0.7 
    +-- chokidar@1.7.0 
    | +-- anymatch@1.3.0 
    | | `-- arrify@1.0.1 
    | +-- async-each@1.0.1 
    | +-- glob-parent@2.0.0 
    | +-- inherits@2.0.3 
    | +-- is-binary-path@1.0.1 
    | | `-- binary-extensions@1.8.0 
    | +-- is-glob@2.0.1 
    | | `-- is-extglob@1.0.0 
    | +-- path-is-absolute@1.0.1 
    | `-- readdirp@2.1.0 
    | +-- minimatch@3.0.4 
    | | `-- brace-expansion@1.1.7 
    | | +-- balanced-match@0.4.2 
    | | `-- concat-map@0.0.1 
    | `-- set-immediate-shim@1.0.1 
    +-- compression@1.6.2 
    | +-- accepts@1.3.3 
    | | `-- negotiator@0.6.1 
    | +-- bytes@2.3.0 
    | +-- compressible@2.0.10 
    | | `-- mime-db@1.27.0 
    | +-- debug@2.2.0 
    | | `-- ms@0.7.1 
    | +-- on-headers@1.0.1 
    | `-- vary@1.1.1 
    +-- connect-history-api-fallback@1.3.0 
    +-- express@4.15.2 
    | +-- array-flatten@1.1.1 
    | +-- content-disposition@0.5.2 
    | +-- content-type@1.0.2 
    | +-- cookie@0.3.1 
    | +-- cookie-signature@1.0.6 
    | +-- debug@2.6.1 
    | | `-- ms@0.7.2 
    | +-- depd@1.1.0 
    | +-- encodeurl@1.0.1 
    | +-- escape-html@1.0.3 
    | +-- etag@1.8.0 
    | +-- finalhandler@1.0.2 
    | | +-- debug@2.6.4 
    | | | `-- ms@0.7.3 
    | | `-- unpipe@1.0.0 
    | +-- fresh@0.5.0 
    | +-- merge-descriptors@1.0.1 
    | +-- methods@1.1.2 
    | +-- on-finished@2.3.0 
    | | `-- ee-first@1.1.1 
    | +-- parseurl@1.3.1 
    | +-- path-to-regexp@0.1.7 
    | +-- proxy-addr@1.1.4 
    | | +-- forwarded@0.1.0 
    | | `-- ipaddr.js@1.3.0 
    | +-- qs@6.4.0 
    | +-- range-parser@1.2.0 
    | +-- send@0.15.1 
    | | +-- debug@2.6.1 
    | | +-- destroy@1.0.4 
    | | +-- http-errors@1.6.1 
    | | `-- ms@0.7.2 
    | +-- serve-static@1.12.1 
    | +-- setprototypeof@1.0.3 
    | +-- statuses@1.3.1 
    | +-- type-is@1.6.15 
    | | `-- media-typer@0.3.0 
    | `-- utils-merge@1.0.0 
    +-- html-entities@1.2.1 
    +-- http-proxy-middleware@0.17.4 
    | +-- http-proxy@1.16.2 
    | | +-- eventemitter3@1.2.0 
    | | `-- requires-port@1.0.0 
    | +-- is-glob@3.1.0 
    | | `-- is-extglob@2.1.1 
    | `-- micromatch@2.3.11 
    | +-- arr-diff@2.0.0 
    | | `-- arr-flatten@1.0.3 
    | +-- array-unique@0.2.1 
    | +-- braces@1.8.5 
    | | +-- expand-range@1.8.2 
    | | | `-- fill-range@2.2.3 
    | | | +-- is-number@2.1.0 
    | | | +-- isobject@2.1.0 
    | | | `-- randomatic@1.1.6 
    | | +-- preserve@0.2.0 
    | | `-- repeat-element@1.1.2 
    | +-- expand-brackets@0.1.5 
    | | `-- is-posix-bracket@0.1.1 
    | +-- extglob@0.3.2 
    | +-- filename-regex@2.0.1 
    | +-- kind-of@3.2.0 
    | | `-- is-buffer@1.1.5 
    | +-- normalize-path@2.1.1 
    | | `-- remove-trailing-separator@1.0.1 
    | +-- object.omit@2.0.1 
    | | +-- for-own@0.1.5 
    | | | `-- for-in@1.0.2 
    | | `-- is-extendable@0.1.1 
    | +-- parse-glob@3.0.4 
    | | +-- glob-base@0.3.0 
    | | `-- is-dotfile@1.0.2 
    | `-- regex-cache@0.4.3 
    |  +-- is-equal-shallow@0.1.3 
    |  `-- is-primitive@2.0.0 
    +-- opn@4.0.2 
    | `-- pinkie-promise@2.0.1 
    | `-- pinkie@2.0.4 
    +-- portfinder@1.0.13 
    | `-- async@1.5.2 
    +-- serve-index@1.8.0 
    | +-- batch@0.5.3 
    | +-- http-errors@1.5.1 
    | | `-- setprototypeof@1.0.2 
    | `-- mime-types@2.1.15 
    +-- sockjs@0.3.18 
    | +-- faye-websocket@0.10.0 
    | | `-- websocket-driver@0.6.5 
    | | `-- websocket-extensions@0.1.1 
    | `-- uuid@2.0.3 
    +-- sockjs-client@1.1.2 
    | +-- eventsource@0.1.6 
    | | `-- original@1.0.0 
    | | `-- url-parse@1.0.5 
    | |  `-- querystringify@0.0.4 
    | +-- faye-websocket@0.11.1 
    | +-- json3@3.3.2 
    | `-- url-parse@1.1.9 
    | `-- querystringify@1.0.0 
    +-- spdy@3.4.4 
    | +-- handle-thing@1.2.5 
    | +-- http-deceiver@1.2.7 
    | +-- select-hose@2.0.0 
    | `-- spdy-transport@2.0.18 
    | +-- hpack.js@2.1.6 
    | +-- obuf@1.1.1 
    | `-- wbuf@1.7.2 
    |  `-- minimalistic-assert@1.0.0 
    +-- strip-ansi@3.0.1 
    | `-- ansi-regex@2.1.1 
    `-- webpack-dev-middleware@1.10.2 
    `-- mime@1.3.4 

npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@^1.0.0 (node_modules\chokidar\node_modules\fsevents): 
npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.1.1: wanted {"os":"darwin","arch":"any"} (current: {"os":"win32","arch":"x64"}) 

，但我不能看到所產生的bundle.js。

如果我運行index.html我不能看到任何東西，但只有一個空白頁。

的Index.html

<!doctype html> 
<html lang="en"> 
    <head> 
    <meta charset="utf-8"> 
    <meta name="viewport" content="width=device-width, initial-scale=1"> 
    <!-- 
     Notice the use of %PUBLIC_URL% in the tag above. 
     It will be replaced with the URL of the `public` folder during the build. 
     Only files inside the `public` folder can be referenced from the HTML. 

     Unlike "/favicon.ico" or "favicon.ico", "%PUBLIC_URL%/favicon.ico" will 
     work correctly both with client-side routing and a non-root public URL. 
     Learn how to configure a non-root public URL by running `npm run build`. 
    --> 
    <title>React App</title> 
    </head> 
    <body> 

    <div id="root"></div> 
    <!-- 
     This HTML file is a template. 
     If you open it directly in the browser, you will see an empty page. 

     You can add webfonts, meta tags, or analytics to this file. 
     The build step will place the bundled scripts into the <body> tag. 

     To begin the development, run `npm start`. 
     To create a production bundle, use `npm run build`. 
    --> 

<script src="/my-app/src/App.js"></script> 
    </body> 
</html> 

App.js

import React, { Component } from 'react'; 
import logo from './logo.svg'; 
import './App.css'; 

class App extends Component { 
    render() { 
    return (
     <div className="App"> 
     <div className="App-header"> 
      <img src={logo} className="App-logo" alt="logo" /> 
      <h2>Welcome to React</h2> 
     </div> 
     <p className="App-intro"> 
      To get started, edit <code>src/App.js</code> and save to reload. 
     </p> 
     </div> 
    ); 
    } 
} 
ReactDOM.render(<App />, document.getElementById('root')) 
export default App; 

的package.json

{ 
    "name": "my-app", 
    "version": "0.1.0", 
    "private": true, 
    "dependencies": { 
    "react": "^15.5.4", 
    "react-dom": "^15.5.4" 
    }, 
    "devDependencies": { 
    "babel-loader": "^7.0.0", 
    "babel-preset-es2015": "^6.24.1", 
    "babel-preset-react": "^6.24.1", 
    "babel-preset-stage-2": "^6.24.1", 
    "react-scripts": "0.9.5", 
    "webpack": "^2.5.1", 
    "webpack-dev-server": "^2.4.5" 
    }, 
    "scripts": { 
    "start": "react-scripts start", 
    "build": "react-scripts build", 
    "dev": "webpack-dev-server --inline --hot", 
    "eject": "react-scripts eject" 
    } 
} 

怎麼回事錯在這裏？請幫忙。謝謝。

編輯：我試圖運行的WebPack我得到的錯誤：

C:\Users\siddhi jambhale\Desktop\react-demo>npm run webpack 
npm ERR! Windows_NT 10.0.14393 
npm ERR! argv "C:\\Program Files\\nodejs\\node.exe" "C:\\Program Files\\nodejs\\node_modules\\npm\\bin\\npm-cli.js" "run" "webpack" 
npm ERR! node v7.10.0 
npm ERR! npm v4.2.0 

npm ERR! missing script: webpack 
npm ERR! 
npm ERR! If you need help, you may report this error at: 
npm ERR!  <https://github.com/npm/npm/issues> 

npm ERR! Please include the following file with any support request: 
npm ERR!  C:\Users\siddhi jambhale\AppData\Roaming\npm-cache\_logs\2017-05-13T05_35_36_577Z-debug.log 

而且bundle.js沒有得到創建時，我要麼安裝的WebPack或運行它。

index.js

import React from 'react'; 
import ReactDOM from 'react-dom'; 
import App from './App'; 
import './index.css'; 

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

Answer 1

你忘了包括bundle.js文件中index.html，就這樣寫：

<body> 
    <div id="root"></div> 
    <script src="bundle.js"></script> 
</body> 

原因：檢查webpack config file：

output: { 
    path: __dirname, 
    filename: "bundle.js" 
} 

當你運行webpack，它將創建一個包含所有代碼的輸出文件bundle.js，您需要將該文件包含在index.html中。