DataTable的GroupBy列和计算字符串列的和

using System;
using System.Data;

class Program
{
    static void Main()
    {
        // 创建一个DataTable并添加数据
        DataTable table = new DataTable();
        table.Columns.Add("Category", typeof(string));
        table.Columns.Add("Value", typeof(string));

        table.Rows.Add("A", "10");
        table.Rows.Add("A", "20");
        table.Rows.Add("B", "30");
        table.Rows.Add("B", "40");

        // 使用GroupBy方法对数据进行分组
        DataTable groupedTable = table.AsEnumerable()
            .GroupBy(row => row.Field<string>("Category"))
            .Select(group => new
            {
                Category = group.Key,
                Sum = group.Sum(row => Convert.ToDouble(row.Field<string>("Value")))
            })
            .CopyToDataTable();

        // 输出分组结果
        foreach (DataRow row in groupedTable.Rows)
        {
            Console.WriteLine("Category: " + row["Category"] + ", Sum: " + row["Sum"]);
        }
    }
}