以编程方式将文件从客户机上传到服务器

我正在用一个简单的应用程序来控制文件上传，它可以自动将文件传输到服务器。

我使用这些示例作为参考，在WebBrowser组件和UploadFileEx中设置一个文件来上传，但在测试时不会在服务器上创建文件!

形式代码:

// simulate this form 
        //<form action ="http://localhost/test.php" method = POST>
        //<input type = text name = uname>
        //<input type = password name =passwd>
        //<input type = FILE name = uploadfile>
        //<input type=submit>

我发现这个类使用HttpWebRequest将文件发送到服务器:

    public static string UploadFileEx(  string uploadfile, string url,
        string fileFormName, string contenttype,NameValueCollection querystring,
        CookieContainer cookies)
    {
        if( (fileFormName== null) ||
            (fileFormName.Length ==0))
        {
            fileFormName = "file";
        }
        if( (contenttype== null) ||
            (contenttype.Length ==0))
        {
            contenttype = "application/octet-stream";
        }

        string postdata;
        postdata = "?";
        if (querystring!=null)
        {
            foreach(string key in querystring.Keys)
            {
                postdata+= key +"=" + querystring.Get(key)+"&";
            }
        }
        Uri uri = new Uri(url+postdata);

        string boundary = "----------" + DateTime.Now.Ticks.ToString("x");
        HttpWebRequest webrequest = (HttpWebRequest)WebRequest.Create(uri);
        webrequest.CookieContainer = cookies;
        webrequest.ContentType = "multipart/form-data; boundary=" + boundary;
        webrequest.Method = "POST";

        // Build up the post message header
        StringBuilder sb = new StringBuilder();
        sb.Append("--");
        sb.Append(boundary);
        sb.Append("'r'n");
        sb.Append("Content-Disposition: form-data; name='"");
        sb.Append(fileFormName);
        sb.Append("'"; filename='"");
        sb.Append(Path.GetFileName(uploadfile));
        sb.Append("'"");
        sb.Append("'r'n");
        sb.Append("Content-Type: ");
        sb.Append(contenttype);
        sb.Append("'r'n");
        sb.Append("'r'n");          
        string postHeader = sb.ToString();
        byte[] postHeaderBytes = Encoding.UTF8.GetBytes(postHeader);
        // Build the trailing boundary string as a byte array
        // ensuring the boundary appears on a line by itself
        byte[] boundaryBytes = Encoding.ASCII.GetBytes("'r'n--" + boundary + "'r'n");
        FileStream fileStream = new FileStream(uploadfile, FileMode.Open, FileAccess.Read);
        long length = postHeaderBytes.Length + fileStream.Length + boundaryBytes.Length;
        webrequest.ContentLength = length;
        Stream requestStream = webrequest.GetRequestStream();
        // Write out our post header
        requestStream.Write(postHeaderBytes, 0, postHeaderBytes.Length);
        // Write out the file contents
        byte[] buffer = new Byte[checked((uint)Math.Min(4096, (int)fileStream.Length))];
        int bytesRead = 0;
        while ( (bytesRead = fileStream.Read(buffer, 0, buffer.Length)) != 0 )
            requestStream.Write(buffer, 0, bytesRead);
        // Write out the trailing boundary
        requestStream.Write(boundaryBytes, 0, boundaryBytes.Length);
        requestStream.Flush();
        requestStream.Close();
        WebResponse responce = webrequest.GetResponse();
        Stream s = responce.GetResponseStream();
        StreamReader sr = new StreamReader(s);
        return sr.ReadToEnd();
    }
    /// <summary>
    /// The main entry point for the application.
    /// </summary>
    [STAThread]
    static void Main(string[] args)
    {
        CookieContainer cookies = new CookieContainer();
        //add or use cookies
        NameValueCollection querystring = new NameValueCollection();
        querystring["uname"]="";
        querystring["passwd"]="";
        string uploadfile;// set to file to upload
        uploadfile = "C:''test.jpg";
        UploadFileEx(uploadfile, "http://127.0.0.1/app/Default.aspx", "uploadfile", "image/pjpeg",
                        querystring, cookies);

    }

在我的情况下，我想使用这个类通过WebBrowser控件，但当我发送邮件到服务器的文件(test.jpg)没有创建!

可能是文件夹权限问题!但是当使用IIS在本地测试时，我得到了同样的问题?

谢谢