示例04 云存储文件上传与访问

示例04 云存储文件上传与访问

对应教程：第 4 章 · 云存储：文件与媒体对象管理

1. 上传文件

const storage = app.storage()

// 前端上传（选择文件后）
async function uploadFile(file) {
  const ext = file.name.split('.').pop()
  const cloudPath = `uploads/${Date.now()}-${Math.random().toString(36).slice(2)}.${ext}`
  
  const res = await storage.uploadFile({
    cloudPath,
    filePath: file  // HTML File 对象
  })
  
  console.log('文件 ID:', res.fileID)
  console.log('下载地址:', res.download_url)
  return res
}
​

2. 获取下载链接

// 获取临时下载链接
const { fileList } = await storage.getDownloadUrl({
  fileList: ['cloud://env-xxx/uploads/avatar.png']
})

fileList.forEach(f => {
  console.log('文件:', f.fileID, '→', f.download_url)
})
​

3. 删除文件

await storage.deleteFile({
  fileList: ['cloud://env-xxx/uploads/old-file.png']
})
​

4. 图片处理（CDN 参数）

// 通过 URL 参数实现图片缩放
const fileID = 'cloud://env-xxx/uploads/photo.jpg'
const { download_url } = await storage.getDownloadUrl({ fileList: [fileID] })

// 缩放到宽 300px
const thumbUrl = `${download_url[0].download_url}?imageMogr2/thumbnail/300x`

// 在 img 标签中使用
// <img src={thumbUrl} alt="缩略图" />
​

5. 云函数中上传文件

// functions/upload/index.js
const cloud = require('@cloudbase/node-sdk')
const app = cloud.init({ env: cloud.SYMBOL_CURRENT_ENV })
const storage = app.storage()
const fs = require('fs')

exports.main = async (event, context) => {
  const { fileContent, fileName } = event
  
  const res = await storage.uploadFile({
    cloudPath: `server-uploads/${Date.now()}-${fileName}`,
    fileContent: Buffer.from(fileContent, 'base64')
  })
  
  return { fileID: res.fileID }
}
​