【react】进阶教程02

import { FixedSizeList as List } from 'react-window';

const BigList = ({ data }) => (
  <List
    height={400}
    itemCount={data.length}
    itemSize={50}
    width={300}
  >
    {({ index, style }) => (
      <div style={style}>Row {data[index]}</div>
    )}
  </List>
);

// 使用
<BigList data={Array(1000).fill().map((_, i) => i)} />

2. 使用 Web Workers 处理 CPU 密集型任务

javascript 复制代码

// worker.js
self.onmessage = (e) => {
  const result = heavyCalculation(e.data);
  self.postMessage(result);
};

// 主线程使用
function App() {
  const [result, setResult] = useState(null);
  const workerRef = useRef(null);

  useEffect(() => {
    workerRef.current = new Worker('worker.js');
    workerRef.current.onmessage = (e) => setResult(e.data);
    return () => workerRef.current.terminate();
  }, []);

  const handleCalculate = () => {
    workerRef.current.postMessage(inputData);
  };

  return (
    <div>
      <button onClick={handleCalculate}>Start Calculation</button>
      {result && <div>Result: {result}</div>}
    </div>
  );
}

二、复杂状态管理场景

1. 全局状态分层（Context + useReducer）

javascript 复制代码

// contexts/authContext.js
const AuthContext = React.createContext();

export function AuthProvider({ children }) {
  const [state, dispatch] = useReducer(authReducer, initialState);

  const login = async (credentials) => {
    dispatch({ type: 'LOGIN_REQUEST' });
    try {
      const user = await api.login(credentials);
      dispatch({ type: 'LOGIN_SUCCESS', payload: user });
    } catch (error) {
      dispatch({ type: 'LOGIN_FAILURE', payload: error });
    }
  };

  return (
    <AuthContext.Provider value={{ ...state, login }}>
      {children}
    </AuthContext.Provider>
  );
}

export const useAuth = () => useContext(AuthContext);

2. 异步状态管理中间件（Redux Thunk）

javascript 复制代码

// store.js
import { configureStore } from '@reduxjs/toolkit';
import { fetchUser } from './userSlice';

const store = configureStore({
  reducer: userReducer,
  middleware: (getDefaultMiddleware) =>
    getDefaultMiddleware().concat(thunkMiddleware),
});

// userSlice.js
export const fetchUser = (userId) => async (dispatch) => {
  dispatch(userLoading());
  try {
    const user = await api.getUser(userId);
    dispatch(userSuccess(user));
  } catch (error) {
    dispatch(userFailure(error));
  }
};

三、高级组件模式扩展

1. 控制反转（Inversion of Control）

javascript 复制代码

function DynamicForm({ fields, onSubmit }) {
  return (
    <form onSubmit={onSubmit}>
      {fields.map((FieldComponent, index) => (
        <FieldComponent key={index} />
      ))}
      <button type="submit">Submit</button>
    </form>
  );
}

// 使用
<DynamicForm
  fields={[TextInput, DatePicker, Dropdown]}
  onSubmit={handleSubmit}
/>

2. Headless 组件模式

javascript 复制代码

function useDropdown(options) {
  const [isOpen, setIsOpen] = useState(false);
  const [selected, setSelected] = useState(null);

  const toggle = () => setIsOpen(!isOpen);

  return {
    isOpen,
    selected,
    toggle,
    options,
    setSelected,
  };
}

// 使用
function CustomDropdown() {
  const dropdown = useDropdown(['Option 1', 'Option 2']);
  return (
    <div className="dropdown">
      <button onClick={dropdown.toggle}>
        {dropdown.selected || 'Select...'}
      </button>
      {dropdown.isOpen && (
        <ul>
          {dropdown.options.map((opt) => (
            <li key={opt} onClick={() => dropdown.setSelected(opt)}>
              {opt}
            </li>
          ))}
        </ul>
      )}
    </div>
  );
}

四、服务端渲染与静态生成（Next.js 集成）

1. 基础 SSR 实现

javascript 复制代码

// pages/index.js
export async function getServerSideProps() {
  const data = await fetch('https://api.example.com/data').then(res => res.json());
  return { props: { data } };
}

export default function HomePage({ data }) {
  return (
    <div>
      <h1>Server-Side Rendered Data</h1>
      <pre>{JSON.stringify(data, null, 2)}</pre>
    </div>
  );
}

2. 静态生成（SSG）

javascript 复制代码

// pages/posts/[id].js
export async function getStaticPaths() {
  const posts = await fetch('https://api.example.com/posts')
    .then(res => res.json());
  const paths = posts.map(post => ({ 
    params: { id: post.id.toString() } 
  }));
  return { paths, fallback: false };
}

export async function getStaticProps({ params }) {
  const post = await fetch(`https://api.example.com/posts/${params.id}`)
          .then(res => res.json());
  return { props: { post } };
}

export default function Post({ post }) {
  return (
    <article>
      <h1>{post.title}</h1>
      <div>{post.content}</div>
    </article>
  );
}

五、动画与交互增强

1. 使用 Framer Motion 实现复杂动画

bash 复制代码

npm install framer-motion

javascript 复制代码

import { motion, AnimatePresence } from 'framer-motion';

function Modal({ isOpen, onClose }) {
  return (
    <AnimatePresence>
      {isOpen && (
        <motion.div
          initial={{ opacity: 0 }}
          animate={{ opacity: 1 }}
          exit={{ opacity: 0 }}
          className="modal"
        >
          <motion.div
            initial={{ y: 50 }}
            animate={{ y: 0 }}
          >
            <button onClick={onClose}>Close</button>
            Modal Content
          </motion.div>
        </motion.div>
      )}
    </AnimatePresence>
  );
}

拖拽交互实现

javascript 复制代码

import { useDrag } from 'react-dnd';

function DraggableItem({ id, text }) {
  const [{ isDragging }, drag] = useDrag(() => ({
    type: 'ITEM',
    item: { id },
    collect: (monitor) => ({
      isDragging: !!monitor.isDragging(),
    }),
  }));

  return (
    <div
      ref={drag}
      style={{ opacity: isDragging ? 0.5 : 1 }}
      className="draggable"
    >
      {text}
    </div>
  );
}

六、工程化最佳实践

1. 项目目录结构规范

javascript 复制代码

src/
├── components/       # 通用组件
├── features/         # 功能模块
│   └── auth/
│       ├── components/  # 模块专用组件
│       ├── hooks/       # 模块自定义 Hooks
│       └── slices/      # Redux Toolkit slices
├── lib/              # 工具函数/第三方集成
├── pages/            # 页面组件（Next.js 路由）
└── stores/           # 全局状态管理

自定义 ESLint 配置

javascript 复制代码

// .eslintrc.js
module.exports = {
  extends: [
    'eslint:recommended',
    'plugin:react/recommended',
    'plugin:react-hooks/recommended',
  ],
  rules: {
    'react/prop-types': 'off',
    'no-unused-vars': 'warn',
    'react-hooks/exhaustive-deps': 'error',
  },
};

七、调试与错误排查

1. React DevTools 高级用法

使用 Profiler 分析组件渲染性能
查看组件 Hooks 依赖关系图
追踪不必要的渲染原因

2. 错误日志收集（Sentry 集成）

javascript 复制代码

// 初始化
import * as Sentry from '@sentry/react';

Sentry.init({
  dsn: 'YOUR_DSN',
  integrations: [new Sentry.BrowserTracing()],
  tracesSampleRate: 1.0,
});

// 错误边界自动捕获
const ErrorBoundary = Sentry.ErrorBoundary;

// 手动捕获
try {
  riskyOperation();
} catch (error) {
  Sentry.captureException(error);
}

八、微前端架构实践

1. 使用 Module Federation

javascript 复制代码

// webpack.config.js (Host)
const { ModuleFederationPlugin } = require('webpack').container;

module.exports = {
  plugins: [
    new ModuleFederationPlugin({
      name: 'host',
      remotes: {
        remoteApp: 'remoteApp@http://localhost:3001/remoteEntry.js',
      },
    }),
  ],
};

// 动态加载远程组件
const RemoteComponent = React.lazy(() => import('remoteApp/Button'));

九、推荐学习路径

实战项目：电商后台管理系统、实时协作工具
源码学习 ：阅读 React 核心算法 reconciler 源码
性能大师：深入研究 React 的 Fiber 架构与调度机制
架构演进：从单体应用到微前端架构的迁移策略

十、扩展工具链

类别	推荐工具
状态管理	Zustand, Jotai
表单处理	React Hook Form
数据请求	SWR, React Query
静态站点	Gatsby
移动端	React Native
桌面端	Electron + React