Uploading to Imageshack with VB.NET
I want to use the http://www.imageshack.us/upload_api.php API function to upload a picture onto ImageShack and then obtain the image_link. The only problem is, how do you place an image with its file name with the form-data along with the API key? This is what is stumping me in trying to implement the function.
By the way, OpenDialog
is already implemented to select the file to upload.
Update: I tried adapting the existing code to use the Unified API and it still does not work. If anyone knows what's wrong in the code, just make the modifications... Otherwise, I would be working on another solution.
Imports System.Xml
Imports System.Xml.Serialization
Imports System.Xml.XPath
Public Class ImageShackUploader
Structure ReturnedURLs
Dim DirectLinkURL As String
Dim yflogURL As String
Dim ThumbnailURL As String
Dim Exitoso As Boolean
End Structure
Private Function GetReturnedURLsFromXMLRta(ByVal XML As String)
'Intitalize new XmlDocument
Dim xmlDoc As New XmlDocument
'Read XML from the string provided
xmlDoc.LoadXml(XML)
'Instantiate the XPathNavigator class.
Dim xmlNav As System.Xml.XPath.XPathNavigator = xmlDoc.CreateNavigator()
'XPath
Dim xmlNI As XPathNodeIterator
'Select XPath
xmlNI = xmlNav.Select("//links")
Dim RtaURLs As New ReturnedURLs
RtaURLs.Exitoso = True
'Get the URLs
While (xmlNI.MoveNext())
Select Case xmlNI.Current.Name
Case "image_link"
RtaURLs.DirectLinkURL = xmlNI.Current.Value
MsgBox("Direct Link: " + xmlNI.Current.Value)
Case "thumb_link"
RtaURLs.ThumbnailURL = xmlNI.Current.Value
MsgBox("Thumbnail Link: " + xmlNI.Current.Value)
Case "yfrog_link"
RtaURLs.yflogURL = xmlNI.Current.Value
MsgBox("yFlog Link: " + xmlNI.Current.Value)
End Select
End While
Return RtaURLs
End Function
Public Function UploadFileToImageShack(ByVal FileName As String) As ReturnedURLs
Dim OldValue As Boolean = System.Net.ServicePointManager.Expect100Continue
Try
System.Net.ServicePointManager.Expect100Continue = False
'1. Cookie
Dim Cookie As New Net.CookieContainer()
'2. Arguments
Dim QueryStringArguments As New Dictionary(Of String, String)
QueryStringArguments.Add("rembar", "1")
QueryStringArguments.Add("key", "")
'3. contentType
Dim ContentType As String = ""
Select Case IO.Path.GetExtension(FileName).ToLower
Case ".jpg"
ContentType = "image/jpeg"
Case ".jpeg"
ContentType = "image/jpeg"
Case ".gif"
ContentType = "image/gif"
Case ".png"
ContentType = "image/png"
Case ".bmp"
ContentType = "image/bmp"
Case ".tif"
ContentType = "image/tiff"
Case ".tiff"
ContentType = "image/tiff"
Case Else
开发者_如何学Python ContentType = "image/unknown"
End Select
'4. Upload and return Rta
Return GetReturnedURLsFromXMLRta(UploadFileEx(FileName, "http://www.imageshack.us/upload_api.php", "fileupload", ContentType, QueryStringArguments, Cookie))
Catch ex As Exception
Dim Rta As New ReturnedURLs
Rta.Exitoso = False
Return Rta
Finally
System.Net.ServicePointManager.Expect100Continue = OldValue
End Try
End Function
Private Function UploadFileEx(ByVal FileName As String, ByVal URL As String, ByVal FileFormName As String, ByVal ContentType As String, ByVal QueryStringArguments As Dictionary(Of String, String), ByVal Cookies As Net.CookieContainer) As String
If FileFormName = "" Then FileFormName = "file"
If ContentType = "" Then ContentType = "application/octet-stream"
Dim PostData As String = "?"
If QueryStringArguments IsNot Nothing Then
For Each kvp As KeyValuePair(Of String, String) In QueryStringArguments
PostData &= kvp.Key & "=" & kvp.Value & "&"
Next
End If
Dim URI As New Uri(URL + PostData)
Dim Boundary As String = "----------" + DateTime.Now.Ticks.ToString("x")
Dim WReq As Net.HttpWebRequest = DirectCast(Net.WebRequest.Create(URI), Net.HttpWebRequest)
WReq.CookieContainer = Cookies
WReq.ContentType = "multipart/form-data; boundary=" + Boundary
WReq.Method = "POST"
Dim PostHeader As String = String.Format("--" & Boundary & "{0}" & _
"Content-Disposition: form-data; name=""" & FileFormName _
& """; fileupload=""" & IO.Path.GetFileName(FileName) & """{0}" _
& "Content-Type: " & ContentType & "{0}{0}", vbNewLine)
Dim PostHeaderBytes As Byte() = System.Text.Encoding.UTF8.GetBytes(PostHeader)
Dim BoundaryBytes As Byte() = System.Text.Encoding.ASCII.GetBytes(vbNewLine & "--" + Boundary + vbNewLine)
Dim FileStream As New IO.FileStream(FileName, IO.FileMode.Open, IO.FileAccess.Read)
WReq.ContentLength = PostHeaderBytes.Length + FileStream.Length + BoundaryBytes.Length
Dim RequestStream As IO.Stream = WReq.GetRequestStream()
RequestStream.Write(PostHeaderBytes, 0, PostHeaderBytes.Length)
Dim buffer As Byte() = New Byte(CInt(Math.Min(4096, CInt(FileStream.Length))) - 1) {}
Dim bytesRead As Integer = 0
Do
bytesRead = FileStream.Read(buffer, 0, buffer.Length)
If bytesRead = 0 Then Exit Do
RequestStream.Write(buffer, 0, bytesRead)
Loop
RequestStream.Write(BoundaryBytes, 0, BoundaryBytes.Length)
RequestStream.Flush()
RequestStream.Close()
Dim Rta As Net.WebResponse = WReq.GetResponse()
Dim s As IO.Stream = Rta.GetResponseStream()
Dim sr As New IO.StreamReader(s)
FileStream.Close()
Return sr.ReadToEnd()
End Function
End Class
Use this library with APIs to uplaod images to ImageShack.
.NET Wrapper For ImageShack XML API. It'll basically take care of all that for you. Resizing, API key, cookies, everything. Just add a reference to the assembly provided, and call it through VB. There's even a demo client provided.
Otherwise: Check out this solution on the ASP.NET forums - Upload Images to ImageShack on ASP.NET forums. The code is in C#, but easily ported to VB.NET.
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