c#比较器辅助类

    /// <summary>
    /// 比较器帮助类
    /// 创建人：苏本东
    /// 创建时间：2019-11-5 11:52:29
    /// </summary>
    public class ComparerHelper<T> : IEqualityComparer<T>
    {
        private readonly Func<T, T, bool> _func;

        /// <summary>
        /// 构造方法
        /// </summary>
        /// <param name="func"></param>
        public ComparerHelper(Func<T, T, bool> func)
        {
            this._func = func;
        }

        /// <summary>
        /// 比较是否相等
        /// </summary>
        /// <param name="x"></param>
        /// <param name="y"></param>
        /// <returns></returns>
        public bool Equals(T x, T y)
        {
            return this._func(x, y);
        }

        /// <summary>
        /// 返回哈希代码
        /// </summary>
        /// <param name="obj"></param>
        /// <returns></returns>
        public int GetHashCode(T obj)
        {
            //说明：此场景，不管obj的hashcode还是obj.id的hashcode都不会相同
            //而如果hashcode不相同，就不会走到equals方法
            //所以我们这里必须返回相同的hashcode，只有这样，equals方法才有机会被执行
            return 1;
        }
    }

   /// <summary>
    /// 检查excel数据是否重复的帮助类
    /// </summary>
    public class CheckExcelDuplicateHelper
    {
        /// <summary>
        /// 检查excel重复数据
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="list">数据集合</param>
        /// <param name="func">条件</param>
        /// <returns></returns>
        public static Response<string> Check<T>(List<T> list, Func<T, T, bool> func) where T : class
        {
            var result = new Response<string>();
            var oldAmount = list.Count;
            list = list.Distinct(new ComparerHelper<T>(func)).ToList();
            var newAmount = list.Count;
            if (oldAmount > newAmount)
            {
                result.Code = 500;
                result.Message = $"不允许有重复数据;";
            }
            return result;
        }
    }

                //检查Excel重复数据
                result = CheckExcelDuplicateHelper.Check(response.Result, (x, y) =>
                {
                    return x.FactoryId == y.FactoryId && x.WorkshopId == y.WorkshopId && x.LineNameCN == y.LineNameCN;
                });