Post on Facebook Wall From GridView

protected void GridView1_RowCommand1(object sender, GridViewCommandEventArgs e)
{
    GridViewRow gvr = (GridViewRow)((Control)e.CommandSource).NamingContainer; 
    int rowIndex = gvr.RowIndex; 
    if (e.CommandName == "Facebook")
    { 
        string app_id = "Your App Id";
        string app_secret = "Your App Secret";
        string scope = "publish_stream,manage_pages,email";
        if (Context.Session["AccessToken"] != null)
        {
            var client = new FacebookClient(Context.Session["AccessToken"].ToString()); 
            client.Post("/me/feed", new
            {
                message = GridView1.Rows[rowIndex].Cells[4].Text,
                name = "C-SharpCorner.Com",
                link = "http://www.c-sharpcorner.com/conference2014/",
                picture = "http://www.c-sharpcorner.com/conference2014/gallery/2013/image1Thumb.jpg",
                description = GridView1.Rows[rowIndex].Cells[3].Text
            });
        }
        else
        {
            Response.Redirect(string.Format(
               "https://graph.facebook.com/oauth/authorize?client_id={0}&redirect_uri={1}&scope={2}"
               app_id, "http://localhost:2754/WebApplication80/WebForm2.aspx", scope));
        }
    }
}

This code will check whether or not an access token is available, in other words whether or not the user is logged in, if the user is not logged in then the Facebook login page will be shown and the user will need to authenticate himself by providing his user name and password, this will create an access token for posting on the user's wall. On getting the user's access token he will be redirected to WebForm2, a new page that I added to my application.

Step 5

Write this code on the page load of WebForm2:

protected void Page_Load(object sender, EventArgs e)
{
    string app_id = "Your App Id";
    string app_secret = "Your App Secret";
    string scope = "publish_stream,manage_pages,email";
    if (Request["code"] != null)
    {
        Dictionary<string, string> tokens = new Dictionary<string, string>();
        string url = string.Format("https://graph.facebook.com/oauth/access_token?
                    client_id={0}&redirect_uri={1}&scope={2}&code={3}&client_secret={4}",
                    app_id, "http://localhost:2754/WebApplication80/WebForm2.aspx", 
                       scope, Request["code"].ToString(), app_secret); 
        HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
        using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)
        {
            StreamReader reader = new StreamReader(response.GetResponseStream()); 
            string vals = reader.ReadToEnd(); 
            foreach (string token in vals.Split('&'))
            {
                tokens.Add(token.Substring(0, token.IndexOf("=")),
                  token.Substring(token.IndexOf("=") + 1, token.Length - token.IndexOf("=") - 1));
            }
        }
        string access_token = tokens["access_token"];
        Context.Session["AccessToken"] = access_token;
        Response.Redirect("~/SharePage.aspx"); 
    }
}

This page uses oauth for posting the content to the Facebook wall, this code will check the app Id and secret Id of the app and will correspondingly grant the permission to post.

It will redirect the user to SharePage.aspx that was our main page. This time share page will get the access token and it's If condition will execute and will post the data.

Output

On running the application you will get an output like this one:

Now I will click on the "Facebook" button and since I was not logged on you can see that the Facebook account is asking me to log in first.

You can see a change in the URL, in other words now it has the access token for posting the data on the Facebook Wall.

Now I click on the button of that row that I want to post to Facebook and you can see that it's posted on my wall.