Uploading Image MultiPart Form HTTPWebRequest - Getting Image Data To String? - vb.net

Question

I am trying to upload a multi-part form with HTTPWebRequest & all is ok until I added an image to upload, mainly I am trying to do exactly the same request as a browser makes which looks like this:
-----------------------------41184676334
Content-Disposition: form-data; name="file"; filename="guitar tape.jpg"
Content-Type: image/jpeg
IMAGEDATAHERE
-----------------------------41184676334
Content-Disposition: form-data; name="save"
save
-----------------------------41184676334--
I am lost on how to format / read the image to set it into the request that I am making below:
Dim boundary As String = "-----------------------------" & DateTime.Now.Ticks.ToString("x")
Dim req As HttpWebRequest = DirectCast(WebRequest.Create("http://www.mysite.com/upload.php"), HttpWebRequest)
req.Method = "POST"
req.ContentType = "multipart/form-data; boundary=" & "---------------------------" & DateTime.Now.Ticks.ToString("x")
req.KeepAlive = False
Dim builder As New StringBuilder()
builder.Append(boundary & vbCrLf & "Content-Disposition: form-data; name=""variable1""" & vbCrLf & vbCrLf & "1" & vbCrLf)
builder.Append(boundary & vbCrLf & "Content-Disposition: form-data; name=""file""; filename=""" & FileName & """" & vbCrLf)
builder.Append("Content-Type: application/octet-stream")
builder.Append(vbCrLf & vbCrLf)
' Add Photo Here
If UpdateImage = True Then
' Load Image
Dim ImageData As System.Drawing.Image
Dim fs As New System.IO.FileStream(ImagePath, System.IO.FileMode.Open)
ImageData = Image.FromStream(fs)
fs.Close()
' Add Image To Header
builder.Append(ImageData)
builder.Append(vbCrLf)
Else
builder.Append(vbCrLf)
End If
builder.Append(boundary & vbCrLf & "Content-Disposition: form-data; name=""save""" & vbCrLf & vbCrLf & "save")
' Footer Bytes
Dim close As Byte() = Encoding.UTF8.GetBytes("--")
Dim postHeader As String = builder.ToString()
Dim postHeaderBytes As Byte() = Encoding.UTF8.GetBytes(postHeader)
Dim boundaryBytes As Byte() = Encoding.ASCII.GetBytes(vbCrLf & boundary & "--" & vbCrLf)
Dim length As Long = postHeaderBytes.Length + boundaryBytes.Length
req.ContentLength = length
Dim requestStream As Stream = req.GetRequestStream()
Dim fulllength As Integer = postHeaderBytes.Length + boundaryBytes.Length
' Write out our post header
requestStream.Write(postHeaderBytes, 0, postHeaderBytes.Length)
' Write out the trailing boundary
requestStream.Write(boundaryBytes, 0, boundaryBytes.Length)
Dim responce As WebResponse
responce = req.GetResponse()
requestStream.Close()
Dim s As Stream = responce.GetResponseStream()
Dim sr As New StreamReader(s)
Dim Content As String = sr.ReadToEnd()
At the moment it is simply posting "System.Drawing.Bitmap" as the image data but I am not sure how to get the same raw data for the image that looks like this:
J©õݨe‚Lnž¿Ëã/ǧúÐ5ý¼C÷Cý>ß’t;fm—=Äw:�/E±ËÙÏ$á#%Pc>× Šgw.²Ab“:ÅÓù:ϯÌh6à€Z§Ó‚g£®hÚD6¨Ø^Ú2ô`ä¨L�YÆÄÅCX#I“ÈÌãj¦L˜•’|¥�Eb¡ëQ–¤Ú, 3\UzL  öÔoj4�•±’u«c¼#„oÕ`îF>·o—ŠûÅ«ÎÑ™¶Ç˜ýº*i°œÈVŒ�Qû”Ñ[.�ÔmçE•ì¦eNCh�Ù
é§�É$m¿ôš"»ÌNæ(VÌmp›F¹XÈ88™ªüµ…d•XµÔÜ#�ˆŠv‘º‚F‚§Yûb
Any ideas on how I could do this or would I need to change my methods?

Answer 1

builder.Append(ImageData)
is not correct. you need read the image as byte, then add the byte[] to the multipart post.
see details at Using HttpWebRequest to POST data/upload image using multipart/form-data
and make sure use a http sniffer (i.e. fiddler) to see what it is actually sending.
first, load image into byte array, then convert it to base64:
imgBase64 = Convert.ToBase64String(my_image_byte_array)

Answer 2

My "OpenFileDialog" name is "file". When a "button" is clicked it will show a pop up dialog for selecting jpg, jpeg, png image files, it can also add bmp or any image file type. Then after the selection of a image file it will show on "PictureBox" i name it as "picboxProfileID".
In Visual Basic:
file.Filter = "image file (*.jpg, *.jpeg, *.png) | *.jpg; *.jpeg; *.png | all files (*.*) | *.*"
If (file.ShowDialog <> Windows.Forms.DialogResult.Cancel) Then
picboxProfileID.Image = Image.FromFile(file.FileName)
picboxProfileID.ImageLocation = file.FileName
txtName.Text = file.FileName
My.Computer.Network.UploadFile(file.FileName, "http://localhost/VTVTS/uploadImageSample.php")
Else
picboxProfileID.Image = Nothing
End If
The destination of the file uploaded will be uploaded on the "images/" of the parent folder php file created.
In PHP:
<?php
$response = array();
$image = $_FILES['file'];
$imageName = $image['name'];
$imageTmpName = $image['tmp_name'];
$imageSize = $image['size'];
$imageError = $image['error'];
$imageType = $image['type'];
$fileExt = explode('.', $imageName);
$fileActualExt = strtolower(end($fileExt));
$allowed = array('jpg', 'jpeg', 'png');
if(in_array($fileActualExt, $allowed)){
$fileNameNew = uniqid('', true).".".$fileActualExt;
$fileDestination = 'images/'.$fileNameNew;
$newDestination = move_uploaded_file($imageTmpName, $fileDestination);
$response['error'] = false;
$response['message'] = "Upload Image Successful";
}else{
$response['error'] = true;
$response['message'] = "You cannot upload files of this type!";
}
echo json_encode($response);
Happy Coding!