Trying to post message to facebook using windows client app

Question

I am using visual studio 2013 .NET 4.5 and C# with a windows forms client application, I am trying to post a message to my own Facebook managed page. I have created a new Facebook application, but not yet published it, I am unsure of the settings, but I have the app_id, app_secret and from debugging I have the access_token.

I used a piece of code to open a browser window to login with permissions and this was successful/

I am getting the following error:

OAuthException - #200) (#200) The user hasn't authorized the application to perform this action

The code I am using is below:

var fb = new FacebookClient("AUTH_CODE")
dynamic parameters = new ExpandoObject();
parameters.message = "hello tweet tweet";
dynamic result = fb.Post("SITE_ID/feed", parameters);
var id = result.id;

for logging in I am using:

var client = new FacebookClient();
client.AppSecret = app_secret;
client.AppId = app_id;
client.AccessToken = "AUTH_CODE";

var fbLoginUri = client.GetLoginUrl(new
{
     client_id = app_id,
     redirect_uri =
     "https://www.facebook.com/connect/login_success.html",
     response_type = "code",
     scope = "manage_pages,offline_access,publish_stream,publish_actions"
});
 System.Diagnostics.Process.Start(url);

I am already logged in and the message on the browser shows SUCCESS...

The DLL that I have referenced is the latest v6.0 Facebook C# SDK

Do I need to setup the Facebook app so that it has permissions to post onto my managed wall and if so how do I do it.

I hope someone out there can help, I have been looking at this for days and I need a little help.

PS:

I have also tried the following code:

        var fb = new FacebookClient();
        dynamic result = fb.Get("oauth/access_token", new
        {
            client_id = app_id,
            client_secret = app_secret,
            grant_type = "client_credentials",
            scope = "manage_pages,offline_access,publish_stream"
        });

        var app_token = result.access_token;

        var client = new FacebookClient(app_token);

        dynamic parameters = new ExpandoObject();
        parameters.message = "Check out this funny article";
        parameters.link = "http://www.natiska.com/article.html";
        parameters.picture = "http://www.natiska.com/dav.png";
        parameters.name = "Article Title";
        parameters.caption = "Caption for the link";

        //446533181408238 is my fan page
        client.Post("/446533181408238/feed", parameters);

Paul.

Answer 1

It seems that the request code from your access token request is missing which probably causes this error, see this question for more details on this.