public void AddChangeGroupAnnouncement(ChangeGroupAnnouncement announcement, string senderId)
        {
            var newAnnouncement = new ChangeGroupAnnouncement()
            {
                Content          = announcement.Content,
                CurrentStatus    = announcement.CurrentStatus,
                DestinationGroup = announcement.DestinationGroup,
                ExpirationDate   = announcement.ExpirationDate,
                FromGroup        = announcement.FromGroup,
                Images           = announcement.Images,
                IssueDate        = announcement.IssueDate,
                Sender           = _studentExchangeDataContext.Users.ToList().Find(s => s.Id == senderId),
                Receivers        = _studentExchangeDataContext.Groups.Include(g => g.Students).ToList().Find(g => g.Id == announcement.DestinationGroup.Id).Students.Cast <UserEntity>().ToList()
            };

            _studentExchangeDataContext.Announcements.Add(newAnnouncement);
            _studentExchangeDataContext.SaveChanges();
        }
 public IHttpActionResult PostChangeGroupAnnouncement([FromBody] ChangeGroupAnnouncement announcement)
 {
     _announcementService.AddChangeGroupAnnouncement(announcement, GetCurrentUserId());
     return(Content(HttpStatusCode.NoContent, ""));
 }