namespace Mvc_Shop.Models

public class Comment
{
    public Comment()
    {
        this.Children = new HashSet<Comment>();

    }
    public int Id { set; get; }

    public string Body { set; get; }

    public System.DateTime CommentDate { get; set; }

    public int? ReplyId { get; set; }

    public ICollection<Comment> Children { get; set; }
    public virtual Comment Reply { set; get; }

    public string User_Id { get; set; }
    [ForeignKey("User_Id")]
    public virtual User User { get; set; }
    public int Product_Id { get; set; }
    [ForeignKey("Product_Id")]
    public virtual Product Product { get; set; }

}

@helper TreeView(IEnumerable<Mvc_Shop.Models.Comment> Comments)

foreach (var item in Comments)

{
    <div class="media">
        <div class="media-body" id="Comment_@(item.Id)" style="padding: 3px;width: 100%;">
            <h4 class="media-heading">
                @item.User.UserName
                <label class="badge pull-left" style="font-weight: normal">@item.CommentDate.ToString("dddd, dd MMMM yyyy - HH:mm")</label>
            </h4>
            <div class="clearfix">
                @item.Body
            </div>
            <fieldset id="reply-cmnt-form_@(item.Id)" class="spr-form-review" style="display:none">
                <div class="spr-form-review-body">
                    @Html.LabelFor(model => model.Comment.Body, new { @class = "spr-form-label" })

                    @Html.TextAreaFor(model => model.Comment.Body, new { @class = "spr-form-input spr-form-input-text", id = "commentbody" + @item.Id })
                    @Html.ValidationMessageFor(model => model.Comment.Body)
                </div>
            </fieldset>
            <a id="btn-hide-div_@(item.Id)" class="btn btn-xs pull-left btn-primary" style="clear: both; display:none" onclick="opencmntdiv(@item.Id);"> بستن</a>
            <a id="btn-send-div_@(item.Id)" class="btn btn-xs pull-left btn-primary" style="clear: both;float:right;display:none" onclick="ReplyComment(@item.Id);"> ارسال پاسخ</a>
            <a id="btn-show-div_@(item.Id)" class="btn btn-xs pull-left btn-primary" style="clear: both" onclick="opencmntdiv(@item.Id);"> پاسخ</a>

        </div>
    </div>
    <hr class="clearfix" />
    if (item.Children.Any())
    {
        @TreeView(item.Children)
    }
}

public ActionResult ShowProducts(string ProductName)
    {
        _dbContext = HttpContext.GetOwinContext().Get<ShopContext>();
        var model = new UserCommentViewModel();
        if (string.IsNullOrEmpty(ProductName))
        {
            return RedirectToAction("Index");
        }
        else
        {
            model.Products = blproduct.Where(p => p.Name.Trim() == ProductName.Trim()).ToList();
            model.Comments = (from u1 in _dbContext.Users
                              join u2 in _dbContext.Comments
                                  on u1.Id equals u2.User.Id
                              where u2.ReplyId == null
                              select new {
                                  Id = u2.Id, Body = u2.Body, CommentDate = u2.CommentDate, User = u1,Children = u2.Children
                              }).ToList().Select(x => new Comment
                              {
                                  Id = x.Id, Body = x.Body, CommentDate = x.CommentDate, User = x.User,Children = x.Children
                              }).ToList();


            if (model != null)
            {
                return View(model);
            }
            else
            {
                return RedirectToAction("Index");
            }
        }
    }