CODEWITHSUNDEEP
vb.netfacebook-graph-apihttpwebrequest
Frank Lombardi
Frank Lombardi

Reputation: 41

Posting image from asp.net (VB.net) to facebook graph api ( error 400 Bad Request )

I am trying to post an image to facebook grap api using asp.net , I know that there is a great post about it here Posting image from .NET to Facebook wall using the Graph API since I need the code in vb.net I just converted the code described over there but while trying to post he picture to facebook I am getting the following error:

The remote server returned an error: (400) Bad Request.

For me is a litle bit hard to debug this error since this is the only request comming from face therefore I don't know if the error is because my form post code is not generated properly or the error is whithin the image I'm trying to send.

I was reading a lot about http form post but still I am not able to figure out where my error is ... acordingly to the Example provided by facebook I believe I do have all the requiered parameters.

Code in facebook example:

      // Show photo upload form to user and post to the Graph URL
     $graph_url= "https://graph.facebook.com/me/photos?"
     . "access_token=" .$access_token;
     echo '<html><body>';
     echo '<form enctype="multipart/form-data" action="'
     .$graph_url .' "method="POST">';
     echo 'Please choose a photo: ';
     echo '<input name="source" type="file"><br/><br/>';
     echo 'Say something about this photo: ';
     echo '<input name="message" 
         type="text" value=""><br/><br/>';
     echo '<input type="submit" value="Upload"/><br/>';
     echo '</form>';
     echo '</body></html>';

my form post generated code (before sending image)

-----------------------------8cf5b7942cad9d0 Content-Disposition: form-data; name="access_token"

DummyAccessTokkenFNC98HZQdkEK7%2foEWpdyFu%2byHu%2bUKAfbTE54aBB5vdHFJaecGHPpGrLCrd5bEZWxlXvVKej0ApDbjEzjki8xzvl28etjRxH1LzcJP314RO5HJDbNbZJ -----------------------------8cf5b7942cad9d0 Content-Disposition: form-data; name="message"

Lombardi likes stackoverflow -----------------------------8cf5b7942cad9d0 Content-Disposition: form-data; name="source"; filename="~\img\taco.jpeg" Content-Type: application/octet-stream

Any help will be highly appreciated .

And this is my full function code 

 Private Function FB_UploadPhoto(ByVal album_id As String, ByVal message As String, ByVal filename As String, ByVal bytes As Byte(), ByVal Token As String) As String

    Dim boundary As String = "---------------------------" + DateTime.Now.Ticks.ToString("x")
    Dim path As String = "https://graph.facebook.com/" '& FacebookID() & "/"

    If Not String.IsNullOrEmpty(album_id) Then
        path += album_id + "/"
    End If
    path += "photos"


    Dim uploadRequest As System.Net.HttpWebRequest
    uploadRequest = CType(System.Net.HttpWebRequest.Create(path), System.Net.HttpWebRequest)
    uploadRequest.ServicePoint.Expect100Continue = False
    uploadRequest.Method = "POST"
    uploadRequest.UserAgent = "Mozilla/4.0 (compatible; Windows NT)"
    uploadRequest.ContentType = "multipart/form-data; boundary=" + boundary
    uploadRequest.KeepAlive = False


    'New string builder

    Dim sb As New System.Text.StringBuilder


    'Add Form Data
    Dim formdataTemplate As String = "--{0}" & vbCrLf & "Content-Disposition: form-data; name=""{1}""" & vbCrLf & vbCrLf & "{2}" & vbCrLf
    'Access Token
    sb.AppendFormat(formdataTemplate, boundary, "access_token", HttpContext.Current.Server.UrlEncode(Token))
    ' Message
    sb.AppendFormat(formdataTemplate, boundary, "message", message)
    'header
    Dim headerTemplate As String = "--{0}" & vbCrLf & "Content-Disposition: form-data; name=""{1}""; filename=""{2}""" & vbCrLf & "Content-Type: {3}" & vbCrLf & vbCrLf
    sb.AppendFormat(headerTemplate, boundary, "source", filename, "application/octet-stream")
    'sb.AppendFormat(headerTemplate, boundary, "source", filename, "image/jpeg")

    Dim formString As String = sb.ToString()
    Dim formBytes As Byte() = Encoding.UTF8.GetBytes(formString)
    Dim trailingBytes As Byte() = Encoding.UTF8.GetBytes("" & vbCrLf & "--" & boundary + "--" & vbCrLf)
    Dim image As Byte()

    If bytes Is Nothing Then
        image = System.IO.File.ReadAllBytes(HttpContext.Current.Server.MapPath(filename))
    Else
        image = bytes
    End If

    'memory stream
    Dim imageMemoryStream As New System.IO.MemoryStream()
    imageMemoryStream.Write(image, 0, image.Length)


    ' Set Content Length
    Dim imageLength As Long = imageMemoryStream.Length
    Dim contentLength As Long = formBytes.Length + imageLength + trailingBytes.Length
    uploadRequest.ContentLength = contentLength


    'Get Request Stream
    uploadRequest.AllowWriteStreamBuffering = False
    Dim strm_out As System.IO.Stream = uploadRequest.GetRequestStream()


    'Write to Stream

    strm_out.Write(formBytes, 0, formBytes.Length)

    Dim buffer As Byte() = New Byte(CType(Math.Min(4096, CType(imageLength, Integer)), UInteger)) {} 'New Byte(CUInt(imageLength)) {} ' New Byte(CUInt(Math.Min(4096, CInt(imageLength)))) {} ' 'New Byte(CUInt(Math.Min(4096, CInt(imageLength)))) {} 'New Byte(CType(Math.Min(4096, CType(imageLength, Integer)), UInteger)) {}
    Dim bytesRead As Integer = 0
    Dim bytesTotal As Integer = 0
    imageMemoryStream.Seek(0, IO.SeekOrigin.Begin)

    'While bytesRead = imageMemoryStream.Read(buffer, 0, buffer.Length) <> 0
    '    strm_out.Write(buffer, 0, bytesRead)
    '    bytesTotal += bytesRead
    'End While
    bytesRead = imageMemoryStream.Read(buffer, 0, buffer.Length)
    While bytesRead <> 0
        strm_out.Write(buffer, 0, bytesRead)
        bytesTotal += bytesRead
        bytesRead = imageMemoryStream.Read(buffer, 0, buffer.Length)
    End While

    strm_out.Write(trailingBytes, 0, trailingBytes.Length)

    'Close Stream
    strm_out.Close()


    'Get Web Response
    Dim response As System.Net.HttpWebResponse = uploadRequest.GetResponse()



    ' Create Stream Reader
    Dim reader As System.IO.StreamReader = New System.IO.StreamReader(response.GetResponseStream())


    Return reader.ReadToEnd()
End Function

Upvotes: 3

Views: 1999

Answers (1)

Frank Lombardi
Frank Lombardi

Reputation: 41

What a blender man ... the problem was the facebook token itself... actually I am encrypting the token seems that my encryption functions are having some sort of issue while decrypting. Anyways I will leave the code over here hopefuly someone else will find useful.

Upvotes: 1

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