www.xiaoheikeji.net?open_id=12
function GetQueryString(name)
{
let reg = new RegExp("(^|&)"+ name +"=([^&]*)(&|$)");
let r = window.location.search.substr(1).match(reg);
if(r!=null)return unescape(r[2]); return null;
}
GetQueryString('open_id') // 12