C#中同一DataTable中合并相同条件的行数据_[Asp.Net教程]

工作中碰到了如题的问题，静下心来研究了一下，如下代码：

using System;
using System.Collections.Generic;
using System.Text;
using System.Text.RegularExpressions;
using System.Collections;
using System.Data;


namespace ConsoleApplication1
{
class Program
{
public static DataTable tabTemp = new DataTable();
public static DataRow drTemp = null;
public static DataTable dt = new DataTable();
static void Main(string[] args)
{
dt.Columns.Add("a", typeof(String));
dt.Columns.Add("b", typeof(String));
dt.Columns.Add("c", typeof(String));
dt.Columns.Add("d", typeof(String));

DataRow dr = null;
dr = dt.NewRow();
dr[0] = "1";
dr[1] = "1";
dr[2] = "1";
dr[3] = "1";
dt.Rows.Add(dr);
dr = dt.NewRow();
dr[0] = "1";
dr[1] = "2";
dr[2] = "2";
dr[3] = "2";
dt.Rows.Add(dr);
dr = dt.NewRow();
dr[0] = "1";
dr[1] = "3";
dr[2] = "3";
dr[3] = "3";
dt.Rows.Add(dr);
dr = dt.NewRow();
dr[0] = "2";
dr[1] = "1";
dr[2] = "1";
dr[3] = "1";
dt.Rows.Add(dr);
dr = dt.NewRow();
dr[0] = "2";
dr[1] = "1";
dr[2] = "1";
dr[3] = "1";
dt.Rows.Add(dr);
dr = dt.NewRow();
dr[0] = "3";
dr[1] = "1";
dr[2] = "1";
dr[3] = "1";
dt.Rows.Add(dr);
Console.WriteLine(dt.Columns[0].ColumnName + " " + dt.Columns[1].ColumnName + " " + dt.Columns[2].ColumnName + " " + dt.Columns[3].ColumnName + " ");
for (int l = 0; l < dt.Rows.Count; l++)
{
Console.WriteLine(dt.Rows[l][0].ToString() + " " + dt.Rows[l][1].ToString() + " " + dt.Rows[l][2].ToString() + " " + dt.Rows[l][3].ToString() + " ");
}
for (int j = 0; j < dt.Columns.Count; j++)
{
tabTemp.Columns.Add(dt.Columns[j].ColumnName, dt.Columns[j].DataType);
}
FindComValue();

Console.WriteLine(tabTemp.Columns[0].ColumnName + " " + tabTemp.Columns[1].ColumnName + " " + tabTemp.Columns[2].ColumnName + " " + tabTemp.Columns[3].ColumnName + " ");
for (int k = 0; k < tabTemp.Rows.Count; k++)
{
Console.WriteLine(tabTemp.Rows[k][0].ToString() + " " + tabTemp.Rows[k][1].ToString() + " " + tabTemp.Rows[k][2].ToString() + " " + tabTemp.Rows[k][3].ToString() + " ");
}
Console.Read();




}

static void FindComValue()
{
if (dt.Rows.Count > 0)
{
string row1 = dt.Rows[0][0].ToString();//取表的第一行第一列
DataRow[] drr = dt.Select("a=" + row1);
drTemp = tabTemp.NewRow();//临时新的行
foreach (DataRow row in drr)
{
for (int i = 0; i < dt.Columns.Count; i++)
{
if (i != 0)
{
if (drTemp[i].ToString().Trim() == "")
drTemp[i] = "0";
drTemp[i] = Convert.ToString(Convert.ToDouble(drTemp[i].ToString()) + Convert.ToDouble(row[i].ToString()));//合并每一列的数据
}
else
{
drTemp[i] = row[i].ToString();//添加第一列，不需要相加
}
}
dt.Rows.Remove(row);//清除此类的行
}
tabTemp.Rows.Add(drTemp);//添加临时新的行数据
FindComValue();
}
}


}
}

来源:网络