moadiran/Shared/DTOs/PromotionDto.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Shared.DTOs
{
    public class PromotionDto
    {
        public int ID { get; set; }
        public string Name { get; set; }
        public decimal TotalPrice { get { return promotionDetails==null ? 0 : promotionDetails.Sum(s => s.TPrice); } }
        public ICollection<PromotionDetailDto> promotionDetails { get; set; }
    }
}