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Editorial Team
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Asked: 2026-06-16T01:50:43+00:00

How would I get raw image data to a String in VB.NET similar to

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How would I get raw image data to a String in VB.NET similar to the following:

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My current code is:

Dim FileName As String = "Image.jpg"
Dim ImageData() As Byte = File.ReadAllBytes(ProfileImagePath)
Dim NewImageData As String = Convert.ToBase64String(ImageData)

This returns the Base64 code but I am trying to get the actual raw data like in the example above so that I can POST to a multipart upload form which also posts in this way.

My full code for the upload being:

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 Byte = File.ReadAllBytes(ProfileImagePath)
            Dim NewImageData As String = Convert.ToBase64String(ImageData)
            ' Add Image To Header
            builder.Append(NewImageData)
            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()
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1 Answer

  1. Editorial Team

    This returns the Base64 code but I am trying to get the actual raw data like in the example above

    The “actual raw data” isn’t text data so you shouldn’t put it in a string at all; at least not without something like base64.

    If you want to post binary data, then either use base64 or post it as raw bytes, but not as text. Your data is not UTF-8-encoded text, so don’t try to use it as if it were.

    (I can’t remember the details of multi-part form data; if you can specify a part length before the part itself, then you should be fine to include the binary data directly. If it’s always just delimited by some separator, then you may want to use base64 instead.)

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