萨姆并减去使用LINQ C＃

Question

我需要返回结果只有一个，我需要总结所有状态(1, 3)和(2, 4, 5)然后减去每个总示例：

cashtransaction_amount, cashtransactionstatus_id 
50.00     1 (+) 
39.99     2 (-) 
330.70     3 (+) 
10.00     5 (-) 
50.50     4 (-) 
30.00     2 (-) 

Sum(1,3): 50.00 + 330.70 = 380.70 
Sum(2, 5, 4): 39.99 + 10.00 + 50.50 + 30.00 = 130.49 
Final Result Sum(1,3) - Sum(2, 5, 4): 380.70 - 130.49 = 250.21 

我tryed：

(from DataRow Transaction_DataRow in Dt_transaction.AsEnumerable() 
where Transaction_DataRow.Field<Int32>("cashpaymenttype_id") == 1 // Cash Money 
group Transaction_DataRow by Transaction_DataRow.Field<Int32>("cashtransactionstatus_id") into tmp 
select new 
    { 
     cashtransaction_amount = tmp.Sum(x => (x.Field<Int32>("cashtransactionstatus_id") == 1 || x.Field<Int32>("cashtransactionstatus_id") == 3) ? x.Field<Double>("cashtransaction_amount") : -x.Field<Double>("cashtransaction_amount")) 
    }).Aggregate(Transaction_DataTable, (dt, result) => { dt.Rows.Add(result.cashtransaction_amount); return dt; }); 

Answer 1

另一种方法是：

total = tmp.Select(b => 
      { 
       var id = b.Field<Int32>("cashtransactionstatus_id"); 
       return (id == 1 || id == 3 ? 1 : -1) * 
         b.Field<Double>("cashtransaction_amount"); 
      }).Sum(); 

或者：

total = tmp.Sum(b => (new[]{1,3}.Contains(b.Field<Int32>("cashtransactionstatus_id")) 
          ? 1 : -1) * b.Field<Double>("cashtransaction_amount")); 

Answer 2

您是否尝试过

cashtransaction_amount = tmp.Aggregate((a,b) => 
    { 
     var id = b.Field<Int32>("cashtransactionstatus_id"); 
     var amt = b.Field<Double>("cashtransaction_amount"); 
     return id == 1 || id == 3 ? a + amt : a - amt; 
    });