DataTable Group by方法

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//需求 對C# DataTable操作,實作Group By功能 實作求總值

IEnumerable<IGrouping<string, DataRow>> data = dt.Rows.Cast<DataRow>().GroupBy<DataRow, string>(dr => dr["列名"].ToString());
            int count = data.Count();
            string[] type = new string[count];
            decimal[] amount = new decimal[count];
            for (int i = 0; i < count; i++)
            {
                IGrouping<string, DataRow> GroupColumn = data.ElementAt(i);
                type[i] = GroupColumn.Key;
                foreach (var detail in GroupColumn)
                {
                    amount[i] += Convert.ToDecimal(f["求和列名"]);
                }
            }

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