how to convert Dynamic in C# to vb?

public dynamic GetPosts()
       {

           var ret = (from post in db.Posts.ToList()
                     orderby post.PostedDate descending
                     select new
                     {
                         Message = post.Message,
                         PostedBy = post.PostedBy,
                         PostedByName = post.UserProfile.UserName,
                         PostedByAvatar =imgFolder +(String.IsNullOrEmpty(post.UserProfile.AvatarExt) ? defaultAvatar : post.PostedBy + "." + post.UserProfile.AvatarExt),
                         PostedDate = post.PostedDate,
                         PostId = post.PostId,
                         PostComments = from comment in post.PostComments.ToList()
                                        orderby comment.CommentedDate
                                        select new
                                        {
                                            CommentedBy = comment.CommentedBy,
                                            CommentedByName = comment.UserProfile.UserName,
                                            CommentedByAvatar = imgFolder +(String.IsNullOrEmpty(comment.UserProfile.AvatarExt) ? defaultAvatar :  comment.CommentedBy + "." + comment.UserProfile.AvatarExt),
                                            CommentedDate = comment.CommentedDate,
                                            CommentId = comment.CommentId,
                                            Message = comment.Message,
                                            PostId = comment.PostId

                                        }
                     }).AsEnumerable();
           return ret;
       }

Public Function GetPosts() As IEnumerable(Of Post)



        Dim ret = (From post In db.Posts.ToList() Order By post.PostedDate Descending Select New With { _
                Key .Message = post.Message, _
                Key .PostedBy = post.PostedBy, _
                Key .PostedByName = post.UserProfile.UserName, _
                Key .PostedByAvatar = imgFolder & Convert.ToString((If([String].IsNullOrEmpty(post.UserProfile.AvatarExt), defaultAvatar, post.PostedBy + "." + post.UserProfile.AvatarExt))), _
                Key .PostedDate = post.PostedDate, _
                Key .PostId = post.PostId, _
                Key .PostComments = From comment In post.PostComments.ToList() Order By comment.CommentedDate Select New With { _
                    Key .CommentedBy = comment.CommentedBy, _
                    Key .CommentedByName = comment.UserProfile.UserName, _
                    Key .CommentedByAvatar = imgFolder & Convert.ToString((If([String].IsNullOrEmpty(comment.UserProfile.AvatarExt), defaultAvatar, comment.CommentedBy + "." + comment.UserProfile.AvatarExt))), _
                    Key .CommentedDate = comment.CommentedDate, _
                    Key .CommentId = comment.CommentId, _
                    Key .Message = comment.Message, _
                    Key .PostId = comment.PostId _
                } _
            }).AsEnumerable()
        Return ret

    End Function