using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using DocumentFormat.OpenXml.Packaging;
using DocumentFormat.OpenXml.Spreadsheet;

namespace ReadExcel
{
  public class Program
  {
    static void Main(string[] args)
    {
      DataTable dt = new DataTable();

      using (SpreadsheetDocument spreadSheetDocument = SpreadsheetDocument.Open(@"Test.xlsx", false))
      {
        WorkbookPart workbookPart = spreadSheetDocument.WorkbookPart;
        IEnumerable<Sheet> sheets = spreadSheetDocument.WorkbookPart.Workbook.GetFirstChild<Sheets>().Elements<Sheet>();
        string relationshipId = sheets.First().Id.Value = sheets.First(x => x.Name == "TestSheet").Id.Value;
        WorksheetPart worksheetPart = (WorksheetPart)spreadSheetDocument.WorkbookPart.GetPartById(relationshipId);
        Worksheet workSheet = worksheetPart.Worksheet;
        SheetData sheetData = workSheet.GetFirstChild<SheetData>();
        Row[] rows = sheetData.Descendants<Row>().ToArray();

        // 设置表头DataTable
        foreach (Cell cell in rows.ElementAt(0))
        {
          dt.Columns.Add((string)GetCellValue(spreadSheetDocument, cell));
        }

        // 添加内容
        for (int rowIndex = 1; rowIndex < rows.Count(); rowIndex++)
        {
          DataRow tempRow = dt.NewRow();

          for (int i = 0; i < rows[rowIndex].Descendants<Cell>().Count(); i++)
          {
            tempRow[i] = GetCellValue(spreadSheetDocument, rows[rowIndex].Descendants<Cell>().ElementAt(i));
          }
          dt.Rows.Add(tempRow);
        }
      }
      Console.ReadKey();
    }

    public static string GetCellValue(SpreadsheetDocument document, Cell cell)
    {
      SharedStringTablePart stringTablePart = document.WorkbookPart.SharedStringTablePart;
      string value = cell.CellValue.InnerXml;

      if (cell.DataType != null && (cell.DataType.Value == CellValues.SharedString || cell.DataType.Value == CellValues.String || cell.DataType.Value == CellValues.Number))
      {
        return stringTablePart.SharedStringTable.ChildElements[Int32.Parse(value)].InnerText;
      }
      else //浮点数和日期对应的cell.DataType都为NULL
      {
        // DateTime.FromOADate((double.Parse(value)); 如果确定是日期就可以直接用过该方法转换为日期对象，可是无法确定DataType==NULL的时候这个CELL 数据到底是浮点型还是日期.(日期被自动转换为浮点
        return value;
      }
    }
  }
}