wx.request里面把responseType设成arraybuffer，然后成功之后wx.arrayBufferToBase64(res.data)转成base64。 getValidateCode:function(){     var that = this;     wx.request({         url: validateCodePath,         method:'get',         responseType: 'arraybuffer',         success:function(res){             const base64 = wx.arrayBufferToBase64(res.data);             that.setData({                 validateCodePath: "data:image/png;base64," + base64             });         }     }) }