我正在尝试使用 asp.net 将图像发布到 facebook grap api， 我知道这里有一篇很棒的帖子 Posting image from .NET to Facebook wall using the Graph API因为我需要 vb.net 中的代码，所以我只是转换了那里描述的代码，但是在尝试将他的图片发布到 facebook 时出现以下错误:
The remote server returned an error: (400) Bad Request.
对我来说，调试这个错误有点困难，因为这是唯一来自面部的请求，所以我不知道这个错误是因为我的表单邮政编码没有正确生成，还是错误在我的图像中正在尝试发送。
我阅读了很多关于 http 表单的帖子，但我仍然无法弄清楚我的错误在哪里......根据 Example provided by facebook我相信我确实拥有所有必需的参数。
Facebook 示例中的代码:
// 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>';
我的表单生成代码(发送图片之前)
----------------------------8cf5b7942cad9d0 Content-Disposition:表单数据； name="access_token"
DummyAccessTokkenFNC98HZQdkEK7%2foEWpdyFu%2byHu%2bUKAfbTE54aBB5vdHFJaecGHPpGrLCrd5bEZWxlXvVKej0ApDbjEzjki8xzvl28etjRxH1LzcJP314RO5HJDbNbZJ ------------------------------8cf5b7942cad9d0 Content-Disposition:表单数据；名称=“消息”
Lombardi 喜欢 stackoverflow ------------------------------8cf5b7942cad9d0 Content-Disposition:表单数据；名称=“来源”；文件名="~\img\taco.jpeg" 内容类型:应用程序/八位字节流
任何帮助将不胜感激。
这是我的完整功能代码
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
最佳答案
真是个 blender 人……问题出在 facebook token 本身……实际上我正在加密 token ，似乎我的加密函数在解密时出现了某种问题。无论如何，我会把代码留在这里，希望其他人会觉得有用。
关于vb.net - 将图像从 asp.net (VB.net) 发布到 facebook graph api(错误 400 错误请求)，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/12334060/