使用Spire.Xls读取Execl文件或IO，导出到 DataTable。

public DataTable ReadExecl(string fileName)
{
	using (var workbook = new Spire.Xls.Workbook())
	{
		workbook.LoadFromFile(fileName);
		using (var sheet = workbook.Worksheets[0])
		{
			return sheet.ExportDataTable();
		}
	}
}