UploadFileEx: C#'s WebClient.UploadFile with more functionality

Imports System
Imports System.Web
Imports System.Collections.Specialized
Imports System.Text
Imports System.Net
Imports System.IO

Public Class Form1

    Public Shared Function UploadFileEx(uploadfile As String, url As String, fileFormName As String, contenttype As String, querystring As NameValueCollection, cookies As CookieContainer) As String
        If (fileFormName Is Nothing) OrElse (fileFormName.Length = 0) Then
            fileFormName = "file"
        End If

        If (contenttype Is Nothing) OrElse (contenttype.Length = 0) Then
            contenttype = "application/octet-stream"
        End If


        Dim postdata As String
        postdata = "?"
        If querystring IsNot Nothing Then
            For Each key As String In querystring.Keys
                postdata += key + "=" + querystring.[Get](key) + "&"
            Next
        End If
        Dim uri As New Uri(url + postdata)


        Dim boundary As String = "----------" + DateTime.Now.Ticks.ToString("x")
        Dim webrequest__1 As HttpWebRequest = DirectCast(WebRequest.Create(uri), HttpWebRequest)
        webrequest__1.CookieContainer = cookies
        webrequest__1.ContentType = "multipart/form-data; boundary=" + boundary
        webrequest__1.Method = "POST"


        ' Build up the post message header
        Dim sb As 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")

        Dim postHeader As String = sb.ToString()
        Dim postHeaderBytes As Byte() = Encoding.UTF8.GetBytes(postHeader)

        ' Build the trailing boundary string as a byte array
        ' ensuring the boundary appears on a line by itself
        Dim boundaryBytes As Byte() = Encoding.ASCII.GetBytes("\r\n--" + boundary + "\r\n")

        Dim fileStream As New FileStream(uploadfile, FileMode.Open, FileAccess.Read)
        Dim length As Long = postHeaderBytes.Length + fileStream.Length + boundaryBytes.Length
        webrequest__1.ContentLength = length

        Dim requestStream As Stream = webrequest__1.GetRequestStream()

        ' Write out our post header
        requestStream.Write(postHeaderBytes, 0, postHeaderBytes.Length)

        ' Write out the file contents
        Dim buffer As Byte() = New [Byte](CUInt(Math.Min(4096, CInt(fileStream.Length))) - 1) {}
        Dim bytesRead As Integer = 0
        While (InlineAssignHelper(bytesRead, fileStream.Read(buffer, 0, buffer.Length))) <> 0
            'sbyte* buffer2 = { 44, 43, 42, 0};
            'String str = new String(buffer2);
            'Console.WriteLine("ISI: " + bytesRead)
            requestStream.Write(buffer, 0, bytesRead)
        End While
        'Console.ReadKey()  'biar consolnya langsung nutup/close

        ' Write out the trailing boundary
        requestStream.Write(boundaryBytes, 0, boundaryBytes.Length)
        requestStream.Flush()
        Dim responce As WebResponse = webrequest__1.GetResponse()
        Dim s As Stream = responce.GetResponseStream()
        Dim sr As New StreamReader(s)

        Return sr.ReadToEnd()
    End Function

    Private Shared Function InlineAssignHelper(Of T)(ByRef target As T, value As T) As T
        target = value
        Return value
    End Function

    Private Sub btnUpload_Click(sender As System.Object, e As System.EventArgs) Handles btnUpload.Click
        Dim cookies As New CookieContainer()
        'add or use cookies

        Dim querystring As New NameValueCollection()

        ' 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>


        querystring("uname") = ""
        querystring("passwd") = ""

        Dim uploadfile As String
        ' set to file to upload
        uploadfile = "D:\nisa.jpg"

        Dim ret As [String] = UploadFileEx(uploadfile, "http://192.168.56.2/webtest/test.php", "file", "image/jpg", querystring, cookies)
        Console.WriteLine(ret)
        'Console.ReadKey()
    End Sub
End Class

uploadfile = @"C:\_User\CHRS\fehlerworkflow.jpg";

           //everything except upload file and url can be left blank if needed

           string outdata = UploadFileEx(uploadfile,
                "http://siedlerchr.bplaced.net/xxxFormular.html", "uploaded", "image/pjpeg",
                querystring, cookies);

<input name="uploaded" type="file" />

<?php
$target = "upload/";
$target = $target . basename( $_FILES['uploaded']['name']) ;

if(move_uploaded_file($_FILES['uploaded']['tmp_name'], $target))
{
echo "The file ". basename( $_FILES['uploadedfile']['name']). " has been uploaded";
}
else {
echo "Sorry, there was a problem uploading your file.";
}
?> 

// Write out the file contents
while (byteCounter < fileData.Length)
{
  if (byteCounter + chunkSize <= fileData.Length)
     requestStream.Write(fileData, byteCounter, chunkSize);

  if (backgorundWorker.CancellationPending)//or other implementation of cancel
  {
        webrequest.Abort();
        requestStream.Close();
  }
}

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");

            ///
            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);

while ((bytesRead = fileStream.Read(buffer, 0, buffer.Length)) != 0)
    requestStream.Write(buffer, 0, bytesRead);

// Write out the trailing boundary

while ((bytesRead = fileStream.Read(buffer, 0, buffer.Length)) != 0)
    requestStream.Write(buffer, 0, bytesRead);
fileStream.Close(); // ! ADDED
// Write out the trailing boundary