如何在c# .net中发送post url请求并获得响应，返回文件下载到本地目录

有人知道我如何发送post请求url并获得响应返回文件下载到c# .net的本地目录吗?我有下面的代码，设法发送一个post url请求和响应与zip文件。如何将文件保存到目录中?

    var client = new WebClient();
    var values = new NameValueCollection();
    values["StartDate"] = "18-Sep-2016 00:00";
    values["EndDate"] = "23-Sep-2016 00:00";
    values["CampaignName"] = "null";
    values["SearchBy"] = "Evaluation";
    values["CustomFilter"] = "rep.CALLDNIS like '#0400000000%'";

    var response = client.UploadValues("http://test.com", values);
    client.DownloadFile(response, @"C:'myfile.zip");