人脸核验成功后 通过 https://api.weixin.qq.com/cityservice/face/identify/getimage?access_token

获取照片转码 var base64 = wx.arrayBufferToBase64(res.data);

照片没办法显示 data:image/png;base64,eyJlcnJjb2RlIjo0ODAwMSwiZXJybXNnIjoiYXBpIHVuYXV0aG9yaXplZCByaWQ6IDYyMzJiZWVlLTYyYjAwMTkzLTU4MDkwYzJjIn0=