HttpWebRequest で認証サーバーに接続してファイルダウンロードを行う方法

HttpWebRequest で認証サーバーに接続してファイルダウンロードを行う方法
VB.NET

Dim webreq As System.Net.HttpWebRequest = _
    CType(System.Net.WebRequest.Create("http://localhost/member/"), _
        System.Net.HttpWebRequest)

webreq.Credentials = New System.Net.NetworkCredential("ユーザー名", "パスワード")

Dim webres As System.Net.HttpWebResponse = _
    CType(webreq.GetResponse(), System.Net.HttpWebResponse)
Dim st As System.IO.Stream = webres.GetResponseStream()
Dim sr As New System.IO.StreamReader(st)
Console.WriteLine(sr.ReadToEnd())
sr.Close()
st.Close()

C#

System.Net.HttpWebRequest webreq = (System.Net.HttpWebRequest)
    System.Net.WebRequest.Create("http://localhost/member/");

webreq.Credentials =
    new System.Net.NetworkCredential("ユーザー名", "パスワード");

System.Net.HttpWebResponse webres =
    (System.Net.HttpWebResponse) webreq.GetResponse();

System.IO.Stream st = webres.GetResponseStream();
System.IO.StreamReader sr = new System.IO.StreamReader(st);
Console.WriteLine(sr.ReadToEnd());
sr.Close();
st.Close();