小程序封装图片上传阿里云OSS

app.js中 写入

wxPromisify(fn) {
  return function (obj = {}) {
    return new Promise((resolve, reject) => {
      obj.success = function (res) {
        resolve(res)
      }
      obj.fail = function (res) {
        reject(res)
      }
      fn(obj)//执行函数，obj为传入函数的参数
    })
  }
}

　　在utils文件夹下新建uploadOssUtil.js文件

let app = getApp();

var uploadFile = app.wxPromisify(wx.uploadFile)
let signObj = null;
// 上传文件到阿里云OSS
function uploadFileToOSS(fileList) {

  return new Promise(function(resolve, reject) {
    let startTime = new Date().getTime()

    // 开始执行上传
    var promise = Promise.all(fileList.map((item, index) => {
      console.log(item)
      return new Promise(function(resolve, reject) {
        console.log("刷新上传凭证")
        wx.request({
         url:"*********",   //调用接口，让后端返回上传所需要的字段
        methods: "get",
         data:"",
        success:res=>{
    if (res.data.code == '20000') {
            signObj = res.data.data;
            var aliyunFileKey;
            console.log("上传参数" + JSON.stringify(item));
            aliyunFieKey=signObj.dir + new Date().getTime() + '_' + item.size + "." + item.type;
            console.log(aliyunFileKey);
            // console.log("上传参数" + JSON.stringify(item))
            uploadFile({
              url: signObj.host, //上传到OSS
              filePath: item.path,
              name: 'file',
              formData: {
                'key': aliyunFileKey,
                'OSSAccessKeyId': signObj.accessid,
                'policy': signObj.policy,
                'signature': signObj.signature,
                'success_action_status': '200'
              }
            }).then(res => {
              item.url = signObj.host + aliyunFileKey;
              console.log(item.url)
              resolve(item)
            })
          } else {
            reject("获取上传凭证失败")
           }
        }
        })
      })
    })).then(res => {
      let endTime = new Date().getTime()
      console.log("上传文件完毕，共耗时：" + (endTime - startTime) + "ms")
      resolve(res)
    })
  })
}

　　

　　最后把文件导出

module.exports = {
  uploadFileToOSS: uploadFileToOSS

};