高分求教：如何写入excel文件
我的程序每次会得出三个数据，我想把这三个数据添加到excel文件的一行，
下一次运行程序时，还要向原来的excel文件写入，需要换行，以前的数据不能被覆盖。
向高手们求教，我是个新手，只要满足我上面的要求就可以，谢谢，希望能讲解的清楚些

------解决方案--------------------
同求，帮顶。。。。。。。。
------解决方案--------------------
private void DSToExecl(string s1,string s2,string s3)
{
string strFile = " ";
string path = " ";
strFile = strFile + "GCOutReport_ ";
strFile = strFile + DateTime.Now.ToString( "yyyyMMddHHmm ");
strFile = strFile + ".xls ";
string fileName = strFile;
path = Server.MapPath(strFile);
//path = "D:\\ " + strFile;
System.IO.FileStream fs = new FileStream(path, System.IO.FileMode.Create, System.IO.FileAccess.Write);
StreamWriter sw = new StreamWriter(fs, new System.Text.UnicodeEncoding());
sw.Write( "表頭1 ");
sw.Write( "\t ");
sw.Write( "表頭2 ");
sw.Write( "\t ");
sw.Write( "表頭3 ");
sw.Write( "\t ");
sw.WriteLine( " ");
for (int i = 0; i < dt.Rows.Count; i++)
{
sw.Write(s1);
sw.Write( "\t ");
sw.Write(s2);
sw.Write( "\t ");
sw.Write(s3);
sw.Write( "\t ");
sw.WriteLine( " ");
}
sw.Flush();
sw.Close();
}

------解决方案--------------------
首先在Excel文件的Sheet1里的第一行第一列输入“数据1”,第二列输入 "数据2 ",第三列输入 "数据3”。存盘退出。

try
{
string strConn = "Provider=Microsoft.Jet.OLEDB.4.0; " + "Data Source= " + Excel文件名 + "; " + "Extended Properties=Excel 8.0; ";
OleDbConnection conn = new OleDbConnection(strConn);
conn.Open();
System.Data.OleDb.OleDbCommand cmd = new OleDbCommand();
cmd.Connection = conn;

cmd.CommandText = "insert into [sheet1$](数据1,数据2,数据3) values(实际数据) ";
cmd.ExecuteNonQuery();
}catch(Exception ex)
{
MessageBox.Show(string.Format( "写入Excel出错:{0} ",ex.Message));
}finally
{
conn.Close();
}