HttpPostRequest Text+File in VB.NET

HttpPostRequest with Files only in VB2008 is easy:

    Using wc As New System.Net.WebClient()
        wc.UploadFile("http://server.de/exemple.php", "c:\test.png")
    End Using

But I want POST Text + Files in one POST (username, password, file). But开发者_Go百科, how to?

This is not possible with WebClient. You will need to use HttpWebRequest and manually format the request according to RFC 1867.