如何通过httppost向SSRS发送参数值数组?

我试图让SSRS生成PDF格式的报告,并捕获字节流以将它们保存到磁盘。如果必须发送的报表参数只有单个值,那么这种方法就可以了,但是如果必须发送特定参数的值数组,那么这种方法就不再有效了。

下面的工作很好,因为我只发送一年的价值。通过UI,Year参数将是multiselect。

        string parameters = "rs:Command=Render&rs:format=PDF&Year=2018"
        byte[] paramHeader = Encoding.ASCII.GetBytes(parameters);
        HttpWebRequest req = (HttpWebRequest)WebRequest.Create(URL);
        req.PreAuthenticate = true;
        req.Credentials = new System.Net.NetworkCredential(
            reportUser,
            reportUserPW,
            reportUserDomain);

        req.Method = "POST";
        req.ContentType = "application/x-www-form-urlencoded";
        req.ContentLength = paramHeader.Length;

        using (var stream = req.GetRequestStream())
        {
            stream.Write(paramHeader, 0, paramHeader.Length);
        }

            HttpWebResponse HttpWResp = (HttpWebResponse)req.GetResponse();
            Stream fStream = HttpWResp.GetResponseStream();
            File.WriteAllBytes(JobId.ToString() + "\\employeeName.pdf", copyStreamToByteArray(fStream));

string parameters = "rs:Command=Render&rs:format=PDF&Year=2018,2017,2016"

当我使用Reports Services UI查看它如何用Fiddler将参数发送到SSRS时,我尝试查看web流量,但无法从中获得任何有用的信息。它看起来像是在一个ViewState字符串中编码的。

如何在Post头中发送给定SSRS参数的值数组?