C uses NOPI library to import Excel documents

Import an Excel document using NOPI

NOPI version: 2.3. 0, SharpZipLib version dependent on NPOI: 0.86, tested for. net 4.0 +

Record several problems encountered

1. IWorkbook interface in NOPI: xls is implemented using HSSFWorkbook class and xlsx is implemented using XSSFWorkbook class

2. Date conversion, judging row. GetCell (j). CellType = = NPOI. SS. UserModel. CellType. Numeric & & HSSFDateUtil.IsCellDateFormatted(row.GetCell(j)

You cannot use row. GetCell (j). DateCellValue directly, it will throw an exception directly

1. Convert file stream to DataTable

  /// <summary>
  ///  According to Excel Format reading Excel
  /// </summary>
  /// <param name="stream"> File stream </param>
  /// <param name="type">Excel Format enumeration type, xls/xlsx</param>
  /// <param name="sheetName"> Table name, default number 1 Zhang </param>
  /// <returns>DataTable</returns>
  private static DataTable ImportExcel(Stream stream, ExcelExtType type, string sheetName)
  {
    DataTable dt = new DataTable();
    IWorkbook workbook;
    try
    {
      //xls Use HSSFWorkbook Class implementation, xlsx Use XSSFWorkbook Class implementation 
      switch (type)
      {
        case ExcelExtType.xlsx:
          workbook = new XSSFWorkbook(stream);
          break;
        default:
          workbook = new HSSFWorkbook(stream);
          break;
      }
      ISheet sheet = null;
      // Get a worksheet   Default rank 1 Zhang 
      if (string.IsNullOrWhiteSpace(sheetName))
        sheet = workbook.GetSheetAt(0);
      else
        sheet = workbook.GetSheet(sheetName);

      if (sheet == null)
        return null;
      IEnumerator rows = sheet.GetRowEnumerator();
      #region  Get header 
      IRow headerRow = sheet.GetRow(0);
      int cellCount = headerRow.LastCellNum;
      for (int j = 0; j < cellCount; j++)
      {
        ICell cell = headerRow.GetCell(j);
        if (cell != null)
        {
          dt.Columns.Add(cell.ToString());
        }
        else
        {
          dt.Columns.Add("");
        }
      }
      #endregion
      #region  Get content 
      for (int i = (sheet.FirstRowNum + 1); i <= sheet.LastRowNum; i++)
      {
        IRow row = sheet.GetRow(i);
        DataRow dataRow = dt.NewRow();

        for (int j = row.FirstCellNum; j < cellCount; j++)
        {
          if (row.GetCell(j) != null)
          {
            // Determine whether the cell is in date format 
            if (row.GetCell(j).CellType == NPOI.SS.UserModel.CellType.Numeric && HSSFDateUtil.IsCellDateFormatted(row.GetCell(j)))
            {
              if (row.GetCell(j).DateCellValue.Year >=1970)
              {
                dataRow[j] = row.GetCell(j).DateCellValue.ToString();
              }
              else
              {
                dataRow[j] = row.GetCell(j).ToString();

              }
            }
            else
            {
              dataRow[j] = row.GetCell(j).ToString();
            }
          }
        }
        dt.Rows.Add(dataRow);
      }
      #endregion

    }
    catch (Exception ex)
    {
      dt=null;
    }
    finally
    {
      //if (stream != null)
      //{
      //  stream.Close();
      //  stream.Dispose();
      //}
    }
    return dt;
  }

2. File upload and import

  /// <summary>
  ///  Upload Excel Import 
  /// </summary>
  /// <param name="file"> Upload file object </param>
  /// <param name="errorMsg"> Error message </param>
  /// <param name="sheetName"> Table name, default number 1 Zhang </param>
  /// <returns></returns>
  public static DataTable Import(System.Web.HttpPostedFileBase file, ref string errorMsg, string sheetName = "")
  {
    if (file == null || file.InputStream == null || file.InputStream.Length == 0)
    {
      errorMsg = " Please select the Excel Documents ";
      return null;
    }
    var excelType = GetExcelFileType(file.FileName);
    if (excelType == null)
    {
      errorMsg = " Please select the correct Excel Documents ";
      return null;
    }
    using (var stream = new MemoryStream())
    {
      file.InputStream.Position = 0;
      file.InputStream.CopyTo(stream);
      var dt = ImportExcel(stream, excelType.Value, sheetName);
      if (dt == null)
        errorMsg = " Import failed , Please select the correct Excel Documents ";
      return dt;
    }
  }

3. Local path read import

  /// <summary>
  ///  Import according to file path Excel
  /// </summary>
  /// <param name="filePath"></param>
  /// <param name="errorMsg"> Error message </param>
  /// <param name="sheetName"> Table name, default number 1 Zhang </param>
  /// <returns> Could be null Adj. DataTable</returns>
  public static DataTable Import(string filePath, ref string errorMsg, string sheetName = "")
  {
    var excelType = GetExcelFileType(filePath);
    if (GetExcelFileType(filePath) == null)
    {
      errorMsg = " Please select the correct Excel Documents ";
      return null;
    }
    if (!File.Exists(filePath))
    {
      errorMsg = " Is not found to import Excel Documents ";
      return null;
    }
    DataTable dt;
    using (var stream = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
    {
      dt = ImportExcel(stream, excelType.Value, sheetName);
    }
    if (dt == null)
      errorMsg = " Import failed , Please select the correct Excel Documents ";
    return dt;
  }

4. Complete demo

One Demo with winform introduced into Excel was added.

https://github.com/yimogit/NopiExcelDemo