获取code并重定向到回调地址链接：
https://open.weixin.qq.com/connect/oauth2/authorize?appid=wx702a005562417853&redirect_uri=http%3A%2F%2Fyangjun.oicp.io%2FWeixin%2Fauthorize.do&response_type=code&scope=snsapi_userinfo&state=STATE&connect_redirect=1#wechat_redirecthttps://open.weixin.
