1.IN的使用；

(1)當多項查詢的是Guid型別時；

#region 將string陣列轉化Guid陣列
                string[] ProjIdList = ProjIdset.Trim().Split(',');
                Guid[] guid_ProjId = new Guid[ProjIdList.Length];
                for (int i = 0; i < ProjIdList.Length; i++)
                {
                    guid_ProjId[i] 
 
= new Guid(ProjIdList[i]);
                }
#endregion

list_data = list_data.Where(p => (guid_ProjId.Contains(p.WareID))).ToList();

(2)當多項查詢的是int型別時；

#region 將string型別轉化為int型別的隱式陣列
             string[] ProjTmId_set = ProjTmIdmodel.Trim().Split(',');
             int?[] ProjTmId_set_num_at = new
 
 int?[ProjTmId_set.Length];
#endregion

DetailList = DetailList.Where(p => (ProjTmId_set_num_at).Contains(p.ProjTmId)).ToList();

(3)當多項查詢的是string型別時；

#region string陣列
              string[] ProjIdList = ProjIdset.Trim().Split(',');
#endregion

list_data = list_data.Where(p => (ProjIdList.Contains(p.WareName))).ToList();

2.Not IN的使用；

(1)當多項查詢的是Guid型別時；

#region 將string陣列轉化Guid陣列
                string[] ProjIdList = ProjIdset.Trim().Split(',');
                Guid[] guid_ProjId = new Guid[ProjIdList.Length];
                for (int i = 0; i < ProjIdList.Length; i++)
                {
                    guid_ProjId[i] = new Guid(ProjIdList[i]);
                }
#endregion

list_data = list_data.Where(p =>!(guid_ProjId.Contains(p.WareID))).ToList();

(2)當多項查詢的是int型別時；

#region 將string型別轉化為int型別的隱式陣列
             string[] ProjTmId_set = ProjTmIdmodel.Trim().Split(',');
             int?[] ProjTmId_set_num_at = new int?[ProjTmId_set.Length];
#endregion

DetailList = DetailList.Where(p => !(ProjTmId_set_num_at).Contains(p.ProjTmId)).ToList();

(3)當多項查詢的是string型別時；

#region string陣列
              string[] ProjIdList = ProjIdset.Trim().Split(',');
#endregion

list_data = list_data.Where(p => !(ProjIdList.Contains(p.WareName))).ToList();

總結：IN與Not IN通過“!”來區分，且除string的型別欄位外，其他型別都需先進行陣列轉換，方可使用！

如果哪裡有寫錯的地方，歡迎指正！

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