using System;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Collections.Generic;
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
DataTable dt = new DataTable();
//DataRow dr = new DataRow();
dt.Columns.Add("C1");
dt.Columns.Add("C2");
dt.Columns.Add("C3");
dt.Columns.Add("C4");
dt.Rows.Add(new string[4]{ "A1", "A2", "a" ,"1"});
dt.Rows.Add(new string[4] { "A1", "A2", "b", "1" });
dt.Rows.Add(new string[4] { "A1", "A2", "c", "1" });
dt.Rows.Add(new string[4] { "B1", "B2", "a", "1" });
CompressTable(dt);
GridView1.DataSource = dt.DefaultView;
GridView1.DataBind();
}
static void CompressTable(DataTable table)
{
Dictionary<string, DataRow> dict = new Dictionary<string, DataRow>(); //這個字典用於查找第一第二列相同的項目
List<DataRow> removeRows = new List<DataRow>(); //這個List 存儲需要刪除的重複行
foreach (DataRow row in table.Rows)
{
string key = row[0].ToString() + ";" + row[1].ToString();
DataRow row1;
if (dict.TryGetValue(key, out row1))
{ //如果找到重複的行,將第三列和第一個重複行的第4列合併
if (row1[3] == DBNull.Value)
{
row1[3] = row[3].ToString();
row1[2] = row[2].ToString();
}
else
{
row1[2] = row1[2].ToString() + ";" + row[2].ToString();
row1[3] = int.Parse(row1[3].ToString())+ int.Parse(row[3].ToString());
} removeRows.Add(row); //將這一行加入要刪除的行列表中
}
else
{
dict.Add(key, row);
}
} //刪除重複的行
foreach (DataRow row in removeRows) { table.Rows.Remove(row); }
}
}運行效果截圖:
