React 进阶阶段学习计划
目标
- 掌握自定义Hooks的创建和使用。
- 深入理解上下文（Context）和Redux的高级用法。
- 学会服务端渲染（SSR）。
- 深入探讨性能优化技巧。
学习内容
自定义Hooks
创建和使用自定义Hooks
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自定义Hooks：用于提取组件逻辑，使代码更加模块化和复用。
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示例：
// useFetch.js import { useState, useEffect } from 'react';function useFetch(url) {const [data, setData] = useState(null);const [loading, setLoading] = useState(true);const [error, setError] = useState(null);useEffect(() => {async function fetchData() {try {const response = await fetch(url);const json = await response.json();setData(json);} catch (err) {setError(err);} finally {setLoading(false);}}fetchData();}, [url]);return { data, loading, error }; }export default useFetch;// App.js import React from 'react'; import useFetch from './useFetch';function App() {const { data, loading, error } = useFetch('https://jsonplaceholder.typicode.com/posts');if (loading) return <div>Loading...</div>;if (error) return <div>Error: {error.message}</div>;return (<div><h1>Data from API</h1><ul>{data.map(item => (<li key={item.id}>{item.title}</li>))}</ul></div>); }export default App;
上下文（Context）和Redux的高级用法
上下文（Context）的高级用法
- Context Consumer：用于在函数组件中消费Context。
- 示例：
// ThemeContext.js import React, { createContext, useContext, useState } from 'react';const ThemeContext = createContext();// 提供者组件 function ThemeProvider({ children }) {const [theme, setTheme] = useState('light');const toggleTheme = () => {setTheme((prevTheme) => (prevTheme === 'light' ? 'dark' : 'light'));};return (<ThemeContext.Provider value={{ theme, toggleTheme }}>{children}</ThemeContext.Provider>); }// 消费者组件 function ThemedButton() {const { theme, toggleTheme } = useContext(ThemeContext);return (<button onClick={toggleTheme} style={{ background: theme === 'light' ? '#fff' : '#333', color: theme === 'light' ? '#000' : '#fff' }}>Toggle Theme</button>); }// App.js import React from 'react'; import ThemeProvider from './ThemeProvider'; import ThemedButton from './ThemedButton';function App() {return (<ThemeProvider><ThemedButton /></ThemeProvider>); }export default App;
Redux的高级用法
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Redux Toolkit：简化Redux的开发流程。
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安装：
npm install @reduxjs/toolkit react-redux -
示例：
// store.js import { configureStore, createSlice } from '@reduxjs/toolkit';const counterSlice = createSlice({name: 'counter',initialState: { value: 0 },reducers: {increment: (state) => {state.value += 1;},decrement: (state) => {state.value -= 1;},}, });const store = configureStore({reducer: {counter: counterSlice.reducer,}, });export const { increment, decrement } = counterSlice.actions; export default store;// App.js import React from 'react'; import { useSelector, useDispatch } from 'react-redux'; import { increment, decrement } from './store'; import { Provider } from 'react-redux'; import store from './store';function Counter() {const count = useSelector((state) => state.counter.value);const dispatch = useDispatch();return (<div><p>Count: {count}</p><button onClick={() => dispatch(increment())}>Increment</button><button onClick={() => dispatch(decrement())}>Decrement</button></div>); }function App() {return (<Provider store={store}><Counter /></Provider>); }export default App;
服务端渲染（SSR）
Next.js
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Next.js：一个流行的React框架，支持服务端渲染。
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安装：
npx create-next-app@latest my-app cd my-app npm run dev -
示例：
// pages/index.js import { useState } from 'react';export default function Home() {const [count, setCount] = useState(0);return (<div><h1>Welcome to Next.js!</h1><p>Count: {count}</p><button onClick={() => setCount(count + 1)}>Increment</button></div>); }// pages/api/hello.js export default function handler(req, res) {res.status(200).json({ name: 'John Doe' }); }
性能优化的深入探讨
使用React Profiler
- React Profiler：用于分析组件的渲染性能。
- 启用Profiler：
import React, { Profiler } from 'react';function onRender(id, phase, actualDuration, baseDuration, startTime, commitTime) {console.log({ id, phase, actualDuration, baseDuration, startTime, commitTime }); }function App() {return (<Profiler id="App" onRender={onRender}><div><h1>React Profiler Example</h1>{/* 其他组件 */}</div></Profiler>); }export default App;
使用React.memo和PureComponent
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React.memo：用于优化函数组件的性能。
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PureComponent：用于优化类组件的性能。
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示例：
// MyComponent.js import React, { PureComponent } from 'react';class MyComponent extends PureComponent {render() {return <div>{this.props.value}</div>;} }export default MyComponent;// MyFunctionComponent.js import React from 'react';const MyFunctionComponent = React.memo(({ value }) => {return <div>{value}</div>; });export default MyFunctionComponent;
实践项目
社交媒体应用
- 创建项目：
npx create-next-app@latest social-media-app cd social-media-app npm run dev - 创建组件：
PostList.js：显示帖子列表import React, { useState, useEffect } from 'react'; import axios from 'axios';function PostList() {const [posts, setPosts] = useState([]);useEffect(() => {axios.get('https://jsonplaceholder.typicode.com/posts').then(response => {setPosts(response.data);}).catch(error => {console.error('Error fetching posts:', error);});}, []);return (<div className="post-list">{posts.map(post => (<div key={post.id} className="post"><h3>{post.title}</h3><p>{post.body}</p></div>))}</div>); }export default PostList;App.js：主组件import React from 'react'; import PostList from '../components/PostList';function Home() {return (<div className="container"><h1>Social Media App</h1><PostList /></div>); }export default Home;
博客管理系统
- 创建项目：
npx create-react-app blog-management --template typescript cd blog-management npm start - 安装axios：
npm install axios - 创建组件：
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PostForm.tsx：添加和编辑帖子的表单import React, { useState } from 'react'; import axios from 'axios';interface Post {id?: number;title: string;content: string; }interface PostFormProps {initialPost?: Post;onSubmit: (post: Post) => void; }const PostForm: React.FC<PostFormProps> = ({ initialPost, onSubmit }) => {const [post, setPost] = useState<Post>({id: initialPost?.id,title: initialPost?.title || '',content: initialPost?.content || '',});const handleSubmit = async (e: React.FormEvent) => {e.preventDefault();onSubmit(post);setPost({ title: '', content: '' });};return (<form onSubmit={handleSubmit}><inputtype="text"value={post.title}onChange={(e) => setPost({ ...post, title: e.target.value })}placeholder="Title"/><textareavalue={post.content}onChange={(e) => setPost({ ...post, content: e.target.value })}placeholder="Content"/><button type="submit">Submit</button></form>); };export default PostForm; -
PostList.tsx：显示帖子列表import React, { useState, useEffect } from 'react'; import axios from 'axios'; import PostForm from './PostForm';interface Post {id: number;title: string;content: string; }const PostList: React.FC = () => {const [posts, setPosts] = useState<Post[]>([]);const [editingPost, setEditingPost] = useState<Post | null>(null);useEffect(() => {axios.get<Post[]>('https://jsonplaceholder.typicode.com/posts').then(response => {setPosts(response.data.slice(0, 10));}).catch(error => {console.error('Error fetching posts:', error);});}, []);const handleEdit = (post: Post) => {setEditingPost(post);};const handleDelete = (postId: number) => {setPosts(posts.filter(post => post.id !== postId));};const handleSave = (post: Post) => {if (post.id) {setPosts(posts.map(p => (p.id === post.id ? post : p)));} else {setPosts([...posts, post]);}setEditingPost(null);};return (<div className="post-list">{editingPost ? (<PostForm initialPost={editingPost} onSubmit={handleSave} />) : (<PostForm onSubmit={handleSave} />)}<ul>{posts.map(post => (<li key={post.id}><h3>{post.title}</h3><p>{post.content}</p><button onClick={() => handleEdit(post)}>Edit</button><button onClick={() => handleDelete(post.id)}>Delete</button></li>))}</ul></div>); };export default PostList; -
App.tsx：主组件import React from 'react'; import PostList from './components/PostList';const App: React.FC = () => {return (<div className="App"><h1>Blog Management System</h1><PostList /></div>); };export default App;
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建议
- 定期回顾：每周花时间回顾本周所学内容，确保知识点牢固掌握。
- 参与社区：加入React相关的论坛、Slack群组或Discord服务器，与其他开发者交流心得。
- 阅读源码：尝试阅读一些复杂的React库的源码，提高代码理解和分析能力。
希望这个学习计划能够帮助你系统地学习React进阶技能，并通过实践项目巩固所学知识。祝你学习顺利！
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