1.安装

 yarn add @umijs/preset-ui -D

2.修改package.json

"scripts": {
    "start": "umi dev",
      //这里修改了启动配置项
    "start:umi-ui": "UMI_UI=1 umi dev",
    "build": "umi build",
    "postinstall": "umi generate tmp",
    "prettier": "prettier --write '**/*.{js,jsx,tsx,ts,less,md,json}'",
    "test": "umi-test",
    "test:coverage": "umi-test --coverage"
  },

3.启动

yarn start