C#或.net中用NPIO要怎样才能导出2007以上的Excel(.xlsx)?

public static void DownData(DataView dvData, string fileName)
{
StringBuilder strBd = new StringBuilder(EXCELHTMLHEAD + "

");
int cols = dvData.Table.Columns.Count;
for (int j = 0; j < cols; j++)
strBd.Append("");
strBd.Append("");

for (int i = 0; i < dvData.Count; i++)
{
strBd.Append("");
for (int j = 0; j < cols; j++)
strBd.Append("");
strBd.Append("");
}
strBd.Append("

" + dvData.Table.Columns[j].Caption + "

" + Lixiang.Common.HtmlToTxt(Convert.ToString(dvData[i][j])) + "

");

DownData(strBd.ToString(), fileName);
}

public const string EXCELHTMLHEAD = @" xmlns:x='urn:schemas-microsoft-com:office:excel' xmlns='http://www.w3.org/TR/REC-html40'>

";