问错误:找不到模块"react-native“/找不到模块:错误:无法解析模块'react-native-web‘

EN

import React from 'react'

import {
AppRegistry,
Component,
...
} from 'react-native';

class App extends Component {
...
}

// App registration and rendering
AppRegistry.registerComponent('App', () => App);
AppRegistry.runApplication('App', { rootTag:     document.getElementById('react-root') });

[Error] ./index.web.js
Module not found: Error: Cannot resolve module 'react-native-web' in /Users/michael/Code/spectrum-react-native
resolve module react-native-web in /Users/michael/Code/spectrum-react-native
  looking for modules in /Users/michael/Code/spectrum-react-native/node_modules
  resolve 'file' react-native-web in /Users/michael/Code/spectrum-react-native/node_modules
  resolve file
    /Users/michael/Code/spectrum-react-native/node_modules/react-native-web is not a file
    /Users/michael/Code/spectrum-react-native/node_modules/react-native-web.webpack.js doesn't exist
    /Users/michael/Code/spectrum-react-native/node_modules/react-native-web.web.js doesn't exist
    /Users/michael/Code/spectrum-react-native/node_modules/react-native-web.js doesn't exist
    /Users/michael/Code/spectrum-react-native/node_modules/react-native-web.json doesn't exist
resolve 'file' or 'directory' /Users/michael/Code/spectrum-react-native/node_modules/react-native-web
  resolve file
    /Users/michael/Code/spectrum-react-native/node_modules/react-native-web is not a file
    /Users/michael/Code/spectrum-react-native/node_modules/react-native-web.webpack.js doesn't exist
    /Users/michael/Code/spectrum-react-native/node_modules/react-native-web.web.js doesn't exist
    /Users/michael/Code/spectrum-react-native/node_modules/react-native-web.js doesn't exist
    /Users/michael/Code/spectrum-react-native/node_modules/react-native-web.json doesn't exist
  resolve directory
    directory default file index
      resolve file index in /Users/michael/Code/spectrum-react-native/node_modules/react-native-web
        /Users/michael/Code/spectrum-react-native/node_modules/react-native-web/index doesn't exist
        /Users/michael/Code/spectrum-react-native/node_modules/react-native-web/index.webpack.js doesn't exist
        /Users/michael/Code/spectrum-react-native/node_modules/react-native-web/index.web.js doesn't exist
        /Users/michael/Code/spectrum-react-native/node_modules/react-native-web/index.js doesn't exist
        /Users/michael/Code/spectrum-react-native/node_modules/react-native-web/index.json doesn't exist
    use dist/index.js from package.json
      resolve 'file' or 'directory' dist/index.js in /Users/michael/Code/spectrum-react-native/node_modules/react-native-web
        resolve file
          /Users/michael/Code/spectrum-react-native/node_modules/react-native-web/dist/index.js doesn't exist
          /Users/michael/Code/spectrum-react-native/node_modules/react-native-web/dist/index.js.webpack.js doesn't exist
          /Users/michael/Code/spectrum-react-native/node_modules/react-native-web/dist/index.js.web.js doesn't exist
          /Users/michael/Code/spectrum-react-native/node_modules/react-native-web/dist/index.js.js doesn't exist
          /Users/michael/Code/spectrum-react-native/node_modules/react-native-web/dist/index.js.json doesn't exist
        resolve directory
          /Users/michael/Code/spectrum-react-native/node_modules/react-native-web/dist/index.js doesn't exist (directory default file)
          /Users/michael/Code/spectrum-react-native/node_modules/react-native-web/dist/index.js/package.json doesn't exist (directory description file)
  ...

 @ ./index.web.js 9:19-42
errors (bundle.js:7934)
onmessage (bundle.js:7969)
dispatchEvent (bundle.js:2874)
(anonymous function) (bundle.js:4908)
forEach
_transportMessage (bundle.js:4906)
(anonymous function)
emit (bundle.js:847)
onmessage (bundle.js:6261)