Delete not working with Web Api - angularjs

Question

When I try to use the DELETE verb I either get a null parameter or the controller doesn't fire.
First I tried this:
[HttpDelete]
public IHttpActionResult Delete(Announcement announcement) {
_unitOfWork.Announcements.Remove(announcement);
_unitOfWork.Complete();
return Ok();
}
The controller fires, but announcement is null. If I check on the client side the parameter is not null, it is a properly formed object.
If I add a Route attribute like the below, then the controller doesn't fire at all.
[HttpDelete]
[Route("api/announcements/{announcement}")]
public IHttpActionResult Delete(Announcement announcement) {
_unitOfWork.Announcements.Remove(announcement);
_unitOfWork.Complete();
return Ok();
}
The client side is initiating the DELETE via angular.
myAPIservice.DeleteAnnouncement = function (announcement) {
console.log('In myAPIservice DeleteAnnouncement');
console.log(announcement);
return $http.delete(serviceURLRoot + 'api/announcements/', announcement, { withCredentials: true }).success(function (data) {
console.log('myAPIservice.DeleteAnnouncement Success');
});
};
EDIT ---
The Announcement class:
public class Announcement {
public int AnnouncementId { get; set; }
public string AnnouncementText { get; set; }
}

Answer 1

You can't send a 'body' with a DELETE call.
You could send the announcement id in the form of a parameter:
myAPIservice.DeleteAnnouncement = function (announcementId) {
console.log('In myAPIservice DeleteAnnouncement');
console.log(announcement);
return $http.delete(serviceURLRoot + 'api/announcements/', announcementId, { withCredentials: true }).success(function (data) {
console.log('myAPIservice.DeleteAnnouncement Success');
});
};
Then retrieve it from your database and delete it server side:
[HttpDelete]
[Route("api/announcements/{announcementId}")]
public IHttpActionResult Delete(int announcementId) {
var announcement = _unitOfWork.GetAnnouncementById(announcementId);
_unitOfWork.Announcements.Remove(announcement);
_unitOfWork.Complete();
return Ok();
}
Or of course delete by id... whatever works.
The important part to note here is that DELETE can't carry a payload / body.