目标：掌握在Vue3中规范地发起HTTP请求

---

1. 安装与基础配置

npm install axios  

javascript">// src/utils/request.js  
import axios from 'axios'  

const service = axios.create({  
  baseURL: 'https://api.example.com',  
  timeout: 10000  
})  

export default service  

---

2. 基础请求示例

<script setup>javascript">  
import request from '@/utils/request'  
import { ref } from 'vue'  

const data = ref(null)  

// GET请求  
const fetchData = async () => {  
  try {  
    const res = await request.get('/posts')  
    data.value = res.data  
  } catch (error) {  
    console.error('请求失败:', error)  
  }  
}  

// POST请求  
const submitForm = async (formData) => {  
  await request.post('/submit', formData)  
}  
</script>  

---

3. 请求/响应拦截器

javascript">// 请求拦截（添加Token）  
service.interceptors.request.use(config => {  
  const token = localStorage.getItem('token')  
  if (token) {  
    config.headers.Authorization = `Bearer ${token}`  
  }  
  return config  
})  

// 响应拦截（统一错误处理）  
service.interceptors.response.use(  
  response => response.data,  
  error => {  
    if (error.response.status === 401) {  
      router.push('/login')  
    }  
    return Promise.reject(error)  
  }  
)  

---

4. 请求封装优化

javascript">// src/api/user.js  
import request from '@/utils/request'  

export const login = (data) => {  
  return request({  
    url: '/user/login',  
    method: 'POST',  
    data  
  })  
}  

export const getUserInfo = () => {  
  return request.get('/user/info')  
}  

---

5. 与Pinia结合使用

javascript">// stores/user.js  
import { defineStore } from 'pinia'  
import { login, getUserInfo } from '@/api/user'  

export const useUserStore = defineStore('user', {  
  state: () => ({  
    token: '',  
    userInfo: null  
  }),  
  actions: {  
    async loginAction(credentials) {  
      const res = await login(credentials)  
      this.token = res.token  
    },  
    async loadUserInfo() {  
      this.userInfo = await getUserInfo()  
    }  
  }  
})  

---

6. 跨域处理（开发环境）

javascript">// vite.config.js  
export default defineConfig({  
  server: {  
    proxy: {  
      '/api': {  
        target: 'http://localhost:3000',  
        changeOrigin: true,  
        rewrite: (path) => path.replace(/^\/api/, '')  
      }  
    }  
  }  
})  

---

最佳实践：

1. 统一错误处理：

javascript">// 在拦截器中全局处理  
const showError = (message) => {  
  ElMessage.error(message || '请求异常')  
}  

2. 取消重复请求：

javascript">// 使用axios.CancelToken避免重复请求  
const pendingRequests = new Map()  

const addPending = (config) => {  
  const key = `${config.method}-${config.url}`  
  config.cancelToken = new axios.CancelToken(cancel => {  
    if (!pendingRequests.has(key)) {  
      pendingRequests.set(key, cancel)  
    }  
  })  
}  

3. Loading状态管理：

<script setup>javascript">  
const isLoading = ref(false)  

const fetchData = async () => {  
  isLoading.value = true  
  try {  
    // ...请求逻辑  
  } finally {  
    isLoading.value = false  
  }  
}  
</script>