获取到的ticket：gQEz8TwAAAAAAAAAAS5odHRwOi8vd2VpeGluLnFxLmNvbS9xLzAyY2JtSGtyN1FjN0QxQTRrVXhyMU4AAgSEGa9bAwSAOgkA
获取二维码网址：https://mp.weixin.qq.com/cgi-bin/showqrcode?ticket=gQEz8TwAAAAAAAAAAS5odHRwOi8vd2VpeGluLnFxLmNvbS9xLzAyY2JtSGtyN1FjN0QxQTRrVXhyMU4AAgSEGa9bAwSAOgkA
这个地址能直接返回二维码二进制图片，不是图片地址。