11装入less

 

    {
      test: /\.less$/,
      exclude: [/node_modules/],
      use: [
          require.resolve('style-loader'),
          {
              loader: require.resolve('css-loader'),
              options: {
                  importLoaders: 1,
                  modules: true,
                  localIdentName:"[name]__[local]___[hash:base64:10]"
              },
          },
          // {
          //     // loader: require.resolve('postcss-loader'),
          // },
          {
              loader: require.resolve('less-loader'), // compiles Less to CSS
          },
        ],
      },


  

要安装less-loader 还有less 模块

要在less里用背景图片，用了相对路径来引入图片 background: url(../assets/img/logo.png);，这时候会报无法解析图片

这是在webpack.config.js里要做设置

      {
        // Exclude `js` files to keep "css" loader working as it injects
        // its runtime that would otherwise processed through "file" loader.
        // Also exclude `html` and `json` extensions so they get processed
        // by webpacks internal loaders.
        // exclude: [/\.(js|jsx|mjs)$/, /\.html$/, /\.json$/],
        test: /\.png$/,
        loader: require.resolve('file-loader'),
        // options: {
        //   name: 'static/media/[name].[hash:8].[ext]',
        // },
      },
    

要用多个样式

        import classNames from 'classnames'
      npm i classnames --save-dev
      className={classNames(styles.left,styles.active)}
    

样式里要给属性设置样式 例如给input里的placeholder设样式

        &::placeholder{
          color:#999
        }


    

要变全局变量就要:global,不管是在什么文件样式里

无法使用箭头函数，这时候要安装

          npm install babel-preset-es2015 --save-dev
          npm install --save-dev babel-preset-stage-0


          .babelrc里面：
          "presets": ["react", "env","es2015","stage-0"],


      

redux

          npm i redux react-redux --save-dev



          import { createStore } from 'redux'
          import reducer from './reducer'

          const store = createStore(reducer)

          export default store




      

        redux
        套路：先创建action,再给store 再去reducer，reducer再返回store,数据更新