return new Promise(function(resolve, reject) {         wx.downloadFile({             url: conf.url + `${url}${data ? "?" + JSON.stringify(data) : ""}`,             header: {                 'Cookie': 'JSESSIONID=' + getApp().globalData.jsessionid             },             success: function(res) {                 if (res.statusCode === 200) {                     console.log(res);                     wx.saveFile({                     tempFilePath: res.tempFilePath,                     success(res){                         console.log(res);                         wx.openDocument({                             filePath: res.savedFilePath,                             success: function (res) {                                 console.log('打开文档成功')                             },                             fail(res){                                 console.log(res);                             }                        })                     },                     fail(res){                         console.log("下载失败")                     }                 })                resolve(res)             } else {                 reject(res)             }             },             fail: function(res) {                 reject(res);             },             complete: function(res) {                 if (complete) complete(res)             },         })     }) [图片]