微信不同域名登录

    #region 调用微信登录方法+void WXloginClike(string id)
    /// 

    /// 登录方法
    /// 

    private void WXloginClike(string id)
    {
        //取得当前域名
        string url = HttpContext.Current.Request.Url.Host;
        //拼接参数
        state = Guid.NewGuid().ToString().Replace("-", "") + "*" + id + "*" + url;
        //把参数传入session方面取出数据
        HttpContext.Current.Session["state"] = state;
        
        string login_url = "https://open.weixin.qq.com/connect/qrconnect?appid=" + client_id + "&redirect_uri=" + Utils.UrlEncode(redirect_uri) + "&response_type=code&scope=snsapi_login&state=" + state;
        //开始发送
        HttpContext.Current.Response.Redirect(login_url);
    }
    #endregion
　　用户扫描二维码后把code和state返回给主域名主域名只做了个交转过程

    ConfigUnit configUnit = new ConfigUnit();
    public void ProcessRequest(HttpContext context)
    {
        if (HttpContext.Current.Request.HttpMethod == "GET")
        {
            //取得state
            string code = configUnit.Read("code");
            string state = configUnit.Read("state");
            if (code == "" && state == "")
            {
                ConfigUnit.ShowMsg("state未初始化", "/index.aspx");
                HttpContext.Current.Response.End();
            }
            //由于之前用了 “*”来分开使用 ，现在借钱出来然后把state和code转交到指定域名实现登录
            string[] sArray = state.Split('*');
            string state1 = sArray[0];
            string callbackTpye = sArray[1];
            string url = "http://" + sArray[2] + "/WXLoginCallback.ashx?state=" + state + "&code=" + code;
            HttpContext.Current.Response.Redirect(url);

        }
    }