在给用户发送消息中涉及到的素材（图片、视频、音频、文章等）需要事先传到微信服务器，然后获得媒体id（media_id），然后把 media_id 传递给用户
上传分上传临时素材（只保存三天）和上传永久素材
上传永久素材只有在认证完成后才有权限
上传素材的提前条件就是获取 access_token，获取方法参考： https://www.cnblogs.com/xiaoliwang/p/10196102.html
这里采用上传的流程为：管理员上传图片到第三方服务器 -> 服务器保存资源获取本地存储路径 -> 将资源上传到微信服务器获取 media_id -> 将本地路径和media_id 一齐存储在数据表中
这里采用multer实现上传
var express = require(‘express‘)var path = require(‘path‘)var router = express.Router()var multer = require(‘multer‘)//uuid工具可以生成唯一标示 需要安装var UUID = require(‘uuid‘)var request = require(‘request‘)var fs = require(‘fs‘)const MediaModel = require(‘../model/media‘)//临时路径var baseApi = `https://api.weixin.qq.com/cgi-bin/media/upload`//永久路径// var baseApi = `https://api.weixin.qq.com/cgi-bin/material/add_material`//设置保存规则var storage = multer.diskStorage({ //destination：字段设置上传路径，可以为函数 destination: path.resolve(__dirname, ‘../upload‘), //filename：设置文件保存的文件名 filename: function(req, file, cb) { let extName = file.originalname.slice(file.originalname.lastIndexOf(‘.‘)) let fileName = UUID.v1() cb(null, fileName + extName) }})//设置过滤规则（可选）var imageFilter = function(req, file, cb){ var acceptableMime = [‘image/jpeg‘, ‘image/png‘, ‘image/jpg‘, ‘image/gif‘] //微信公众号只接收上述四种类型的图片 if(acceptableMime.indexOf(file.mimetype) !== -1){ cb(null, true) }else{ cb(null, false) }}//设置限制（可选）var imageLimit = { fieldSize: ‘2MB‘}//创建 multer 实例var imageUploader = multer({ storage: storage, fileFilter: imageFilter, limits: imageLimit}).array(‘photos‘, 12) //定义表单字段、数量限制var videoFilter = function(req, file, cb){ var acceptableMime = [‘video/mp4‘] //微信公众号只接收上述四种类型的图片 if(acceptableMime.indexOf(file.mimetype) !== -1){ cb(null, true) }else{ cb(null, false) }}var videoUploader = multer({ storage: storage, fileFilter: videoFilter, limits: { fieldSize: ‘10MB‘ }}).array(‘video‘, 10)router.post(‘/image‘, imageUploader, function(req, res, next) { var api = `${baseApi}?access_token=${global.accessToken}&type=image` req.files.forEach(file => { var formData = { media: fs.createReadStream(file.path) } request.post({url: api, formData: formData}, function(err,response,body){ if(err) { console.log(‘上传图片失败‘ , err); return } let data = { media_id: JSON.parse(response.body).media_id, local_url: path.join(path.resolve(__dirname, ‘../upload‘), file.filename), type: ‘image‘ }
//保存数据库 MediaModel.create(data).then(res => { console.log(`保存图片${res.dataValues.media_id}成功`); }) }) })})router.post(‘/video‘, videoUploader, function(req, res, next) { console.log(req.files);})module.exports = router
