1.多引數

判斷 條件 

          //判斷
            var fileKey = new
            {
                DateStart = search.DateStart.IsNull(), //關開始時間
                DateEnd = search.DateEnd.IsNull(), //結束時間
                UserName = search.UserName.IsNullOrEmpty(), //使用者名稱
                NickName = search.NickName.IsNullOrEmpty(), //
 
暱稱
                PhoneNumber = search.PhoneNumber.IsNullOrEmpty(), //電話號碼
                ProblemCatey = search.ProblemCatey.IsNullOrEmpty(), //問題種類
            };
      

IsNull()  和 IsNullOrEmpry() 是拓展靜態方法

        /// <summary>
        /// 驗證字串是否為空字串
        /// </summary>
        /// <param name="self"></param>
 

        /// <returns></returns>
        public static bool IsNullOrEmpty(this string self)
        {
            if (self == null || self.Length == 0)
            {
                return true;
            }
            return false;
        }

使用如下

            //查詢
            var list =
                from
 
 p in
                    unitOfWork.FeedBack.Get(p => (fileKey.ProblemCatey || p.ProblemCatey.Contains(search.ProblemCatey)))
                join m in unitOfWork.Member.Get() on p.UserID equals m.Id

                where fileKey.UserName || m.UserName.Contains(search.UserName)
                where fileKey.NickName || m.NickName.Contains(search.NickName)
                where fileKey.PhoneNumber || m.PhoneNumber.Contains(search.PhoneNumber)

                where fileKey.DateStart || p.CreatedOn >= search.DateStart
                where fileKey.DateEnd || p.CreatedOn <= search.DateEnd

                select new FeedBackModelExd
                {
                    Id = p.Id,
                    ProblemCatey = p.ProblemCatey,
                    CreatedOn = p.CreatedOn,
                    UserName = m.UserName,
                    NickName = m.NickName,
                    PhoneNumber = m.PhoneNumber,
                    Content = p.Content,
                };

2.單一引數

改造前

 private static bool TraditionalVerify(int number)
   2:          {
   3:              if ((number > 0) && (number >= 10) && (number % 2 > 0) && (number * 2 > 100))
   4:              {
   5:                  return true;
   6:              }
   7:              return false;
   8:          }

改造後

8:          private static bool UseFunc(int number)
   9:          {
  10:              var conditionlist = new List<Func<bool>>()
  11:              {
  12:                   () => number > 0,
  13:                   () => number >= 10,
  14:                   () => number % 2 > 0,
  15:                   () => number * 2 > 100
  16:              };
  17:   
  18:              return conditionlist.TrueForAll(foo => foo.Invoke());
  19:          }

無論多引數還是單一引數，都可以 以此思想拓展，合適你的需求即可。