如何使用OpenXml将Excel中的多个工作表解析为数据集

我搜索了很多关于如何使用开放XML读取和复制多个Excel工作表中的数据到数据集的信息。只得到如何解析单表excel数据表。我有一个Excel文件与多个表。我想把数据放到数据集中，所以下面我粘贴了复制一个工作表数据的代码。请帮我阅读多个表格excel数据集。

public static DataTable ReadAsDataTable(string fileName)
{
    DataTable dataTable = new DataTable();
    using (SpreadsheetDocument spreadSheetDocument = SpreadsheetDocument.Open(fileName, false))
    {
        WorkbookPart workbookPart = spreadSheetDocument.WorkbookPart;
        IEnumerable<Sheet> sheets = spreadSheetDocument.WorkbookPart.Workbook.GetFirstChild<Sheets>().Elements<Sheet>();
        string relationshipId = sheets.First().Id.Value;
        WorksheetPart worksheetPart = (WorksheetPart)spreadSheetDocument.WorkbookPart.GetPartById(relationshipId);
        Worksheet workSheet = worksheetPart.Worksheet;
        SheetData sheetData = workSheet.GetFirstChild<SheetData>();
        IEnumerable<Row> rows = sheetData.Descendants<Row>();
        foreach (Cell cell in rows.ElementAt(0))
        {
            dataTable.Columns.Add(GetCellValue(spreadSheetDocument, cell));
        }
        foreach (Row row in rows)
        {
            DataRow dataRow = dataTable.NewRow();
            for (int i = 0; i < row.Descendants<Cell>().Count(); i++)
            {
                dataRow[i] = GetCellValue(spreadSheetDocument, row.Descendants<Cell>().ElementAt(i));
            }
            dataTable.Rows.Add(dataRow);
        }
    }
    dataTable.Rows.RemoveAt(0);
    return dataTable;
}