(VB.NET UWP/WinRT) Facebook Upload Photo from Local File

Uploads a new photo with a caption from a local file.

Chilkat Universal Windows Platform (UWP) / WinRT Downloads Chilkat for the Universal Windows Platform (UWP)

' This example assumes Chilkat HTTP to have been previously unlocked.
' See Global Unlock Sample for sample code.

Dim http As New Chilkat.Http

Dim req As New Chilkat.HttpRequest
req.HttpVerb = "POST"
req.ContentType = "multipart/form-data"
req.Path = "/v2.7/me/photos"

' Use the previously obtained access token.
' Note: The publish_actions scope is required to upload a photo.
req.AddHeader("Authorization","Bearer FACEBOOK-ACCESS-TOKEN")

' Send an "Expect: 100-continue" header in the request.
' This causes the HTTP server to end a 100-continue response
' immediately after receiving the HTTP header.  The client
' (Chilkat) will receive this intermediate response, and if
' it's not an error response, it knows that the HTTP server will
' accept the data that is forthcoming.
' The alternative is to get an error response after trying to upload
' the entire contents of the files.
req.AddHeader("Expect","100-continue")

' Set a photo caption.
req.AddParam("caption","Here are some penguins!")

' Additional parameters can be added to the request by 
' calling AddParam once per parameter.  
' See https://developers.facebook.com/docs/graph-api/reference/user/photos
' for more information about other optional parameters.

' Indicate the local file to be uploaded.
Dim success As Boolean = req.AddFileForUpload("source","qa_data/jpg/penguins2.jpg")
If (success <> True) Then
    Debug.WriteLine(req.LastErrorText)
    Exit Sub
End If


' Upload the image file..
Dim resp As Chilkat.HttpResponse = Await http.SynchronousRequestAsync("graph.facebook.com",443,True,req)
If (http.LastMethodSuccess <> True) Then
    Debug.WriteLine(http.LastErrorText)
    Exit Sub
End If


' Examine the response body:
Dim responseJson As String = resp.BodyStr
Debug.WriteLine(responseJson)

' The response contains JSON, such as this:
' {"id":"10210224963435862","post_id":"10224048320139890_10210224963435862"}