react-hot-loader的用法是什么

npm install --save-dev react-hot-loader

npm install --save-dev webpack-dev-server

var webpack = require('webpack');
var WebpackDevServer = require('webpack-dev-server');
var config = require('./webpack.config');
new WebpackDevServer(webpack(config), {
  publicPath: config.output.publicPath,
  hot: true,
  historyApiFallback: true
}).listen(3000, 'localhost', function (err, result) {
  if (err) {
    return console.log(err);
  }
  console.log('Listening at http://localhost:3000/')
});
配置 webpack.config.js
然后在 webpack 的配置文件里添加 react-hot-loader。
打开 webpack.config.js
var webpack = require('webpack');
module.exports = {
  // 修改 entry
  entry: [
    // 写在入口文件之前
    "webpack-dev-server/client?http://0.0.0.0:3000",
    "webpack/hot/only-dev-server",
    // 这里是你的入口文件
    "./src/app.js",
  ],
  output: {
    path: __dirname,
    filename: "build/js/bundle.js",
    publicPath: "/build"
  },
  module: {
    loaders: [
      {
        test: /\.jsx?$/,
        exclude: /node_modules/,
        // 在这里添加 react-hot，注意这里使用的是loaders，所以不能用 query，应该把presets参数写在 babel 的后面
        loaders: ['react-hot', 'babel?presets[]=react,presets[]=es2015']
      }
    ]
  },
  // 添加插件
  plugins: [
    new webpack.HotModuleReplacementPlugin()
  ]

webpack --display-error-details --progress --colors --watch