webpack.config.dev.js和webpack.config.pro.js找到module里面css的相关配置在options配置里面加上一下两句代码

              options: {
                 importLoaders: 1,
                  // 改动
                  modules: true,   // 新增对css modules的支持
                  localIdentName: '[name]__[local]__[hash:base64:5]', //
                },

如果再项目中用到antd的时候，会发现antd的样式无效了，这个时候我们可以做一个处理：:将antd组件的css的webpack配置和非antd组件的csswebpack配置分开

 {
            test: /\.(css|less)$/,
            exclude: /node_modules|antd\.css/,
            use: [
              require.resolve('style-loader'),
              {
                loader: require.resolve('css-loader'),
                options: {
                  importLoaders: 1,
                  // 改动
                  modules: true,   // 新增对css modules的支持
                  localIdentName: '[name]__[local]__[hash:base64:5]', //
                },
              },
              {
                loader: require.resolve('postcss-loader'),
                options: {
                  // Necessary for external CSS imports to work
                  // https://github.com/facebookincubator/create-react-app/issues/2677
                  ident: 'postcss',
                  plugins: () => [
                    require('postcss-flexbugs-fixes'),
                    autoprefixer({
                      browsers: [
                        '>1%',
                        'last 4 versions',
                        'Firefox ESR',
                        'not ie < 9', // React doesn't support IE8 anyway
                      ],
                      flexbox: 'no-2009',
                    }),
                  ],
                },
              },
              {
                loader: require.resolve('less-loader') // compiles Less to CSS
              }
            ],
          },
          {
            test: /\.(css|less)$/,
            include: /node_modules|antd\.css/,
            use: [
              require.resolve('style-loader'),
              {
                loader: require.resolve('css-loader'),
                options: {
                  importLoaders: 1,
                },
              },
              {
                loader: require.resolve('postcss-loader'),
                options: {
                  // Necessary for external CSS imports to work
                  // https://github.com/facebookincubator/create-react-app/issues/2677
                  ident: 'postcss',
                  plugins: () => [
                    require('postcss-flexbugs-fixes'),
                    autoprefixer({
                      browsers: [
                        '>1%',
                        'last 4 versions',
                        'Firefox ESR',
                        'not ie < 9', // React doesn't support IE8 anyway
                      ],
                      flexbox: 'no-2009',
                    }),
                  ],
                },
              },
              {
                loader: require.resolve('less-loader') // compiles Less to CSS
              }
            ],
          },