public IActionResult Create(CreateTopicBindingModel model)
        {
            if (!this.ModelState.IsValid)
            {
                return(this.View());
            }

            return(null);
        }
        public async Task CreateTopicAsync(CreateTopicBindingModel model)
        {
            var author = await _dbContext.Users.FirstOrDefaultAsync(a => a.UserName == model.Author);

            var topic = new Topic
            {
                Title     = model.Title,
                Content   = model.Content,
                AuthorId  = author.Id,
                Author    = (User)_dbContext.Users.FirstOrDefault(a => a.Id == author.Id),
                CreatedOn = model.CreatedOn
            };

            await _dbContext.Topics.AddAsync(topic);

            await _dbContext.SaveChangesAsync();
        }
        public async Task <IActionResult> Create(CreateTopicBindingModel model)
        {
            await _service.CreateTopicAsync(model);

            return(RedirectToAction("Index", "Home"));
        }