我在base.js寫(xiě)好了公共類，然后在index.js引用，問(wèn)題在獲取圖片ajax這個(gè)方法最后return為undefined以下是base.js的代碼import{Config}from'./config.js';import{mockData}from'./mockData.js';classBase{constructor(){this.API_HOST=Config.API_HOST;this.DEBUG=Config.DEBUG;}//http請(qǐng)求類ajax(params,callback){varurl=this.API_HOST+params.url;if(params.loginUrl==undefined){params.loginUrl='../../login/login'}if(params.responseType==undefined){params.responseType='text'}wx.request({url:url,data:params.data,method:params.type,responseType:params.responseType,header:{'content-type':'application/x-www-form-urlencoded','Authorization':wx.getStorageSync('loginFlag')},success:function(res){//未登錄if(res.data.code==106||res.data.code==107||res.data.code==108){wx.reLaunch({url:params.loginUrl})}//如果Authorization不為undefined則重新賦值loginFlagletloginFlag=res.header.Authorizationif(loginFlag!=undefined||loginFlag!=null){wx.setStorageSync('loginFlag',res.header.Authorization)}//如果callback存在，就執(zhí)行callback(res)callback&&callback(res)},fail:function(err){//console.log(JSON.stringify(err)+'這里是base的錯(cuò)誤函數(shù)')}})}//獲取圖片ajaximgAjax(id){var_this=this;varimgUrl;varparams={'url':'file/fileController/download?id='+id,'type':'GET','responseType':'arraybuffer'}//returnparamsthis.ajax(params,function(res){//console.log(res,'圖片在這');letbase64=wx.arrayBufferToBase64(res.data);imgUrl='data:image/jpg;base64,'+base64;console.log(imgUrl,"imgUrl")returnimgUrl//問(wèn)題在這里return為什么是undefined})}}export{Base}下面是index.js的代碼ceshi:function(){console.log(base.imgAjax('2c91808b6d667186016d6672d9ff0007'),"ceshi")}