Filing issue based on discussions on Stackoverflow (http://facebook.stackoverflow.com/questions/8875134/post-to-likes-only-works-after-get-bug-or-by-design
My app has permissions to "like" something on FB on a user's behalf. Using the Facebook C# SDK (5.4.1), here's what I wrote:
Facebook.FacebookClient fb = new Facebook.FacebookClient(AccessToken);
object o = fb.Get("1234567890_12345678901234567/likes");
dynamic parameters = new ExpandoObject();
dynamic success = fb.Post("1234567890_12345678901234567/likes", parameters);
The second line is superfluous and creates an unnecessary round-trip, as we're not interested in the other "likes" on the same object. However, without it, fb.Post fails and throws "The remote server returned an error: (400) Bad Request."
Is this a bug in the C# SDK, or a bug in the graph API, or is it by design?
Note that it's possible to POST to /comments without a previous GET.