C#使用NOPI库实现导入Excel文档

使用nopi导入excel文档

nopi版本：2.3.0,依赖于npoi的sharpziplib版本：0.86,经测试适用于.net4.0+

记录遇到的几个问题

1.nopi中的iworkbook接口：xls使用hssfworkbook类实现，xlsx使用xssfworkbook类实现

2.日期转换，判断row.getcell(j).celltype == npoi.ss.usermodel.celltype.numeric && hssfdateutil.iscelldateformatted(row.getcell(j)

不能直接使用row.getcell(j).datecellvalue,这玩意会直接抛出异常来~

1. 将文件流转换为datatable

  /// <summary>
  /// 根据excel格式读取excel
  /// </summary>
  /// <param name="stream">文件流</param>
  /// <param name="type">excel格式枚举类型，xls/xlsx</param>
  /// <param name="sheetname">表名，默认取第一张</param>
  /// <returns>datatable</returns>
  private static datatable importexcel(stream stream, excelexttype type, string sheetname)
  {
    datatable dt = new datatable();
    iworkbook workbook;
    try
    {
      //xls使用hssfworkbook类实现，xlsx使用xssfworkbook类实现
      switch (type)
      {
        case excelexttype.xlsx:
          workbook = new xssfworkbook(stream);
          break;
        default:
          workbook = new hssfworkbook(stream);
          break;
      }
      isheet sheet = null;
      //获取工作表 默认取第一张
      if (string.isnullorwhitespace(sheetname))
        sheet = workbook.getsheetat(0);
      else
        sheet = workbook.getsheet(sheetname);

      if (sheet == null)
        return null;
      ienumerator rows = sheet.getrowenumerator();
      #region 获取表头
      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 获取内容
      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)
          {
            //判断单元格是否为日期格式
            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. 文件上载导入

  /// <summary>
  /// 上传excel导入
  /// </summary>
  /// <param name="file">上载文件对象</param>
  /// <param name="errormsg">错误信息</param>
  /// <param name="sheetname">表名，默认取第一张</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 = "请选择要导入的excel文件";
      return null;
    }
    var exceltype = getexcelfiletype(file.filename);
    if (exceltype == null)
    {
      errormsg = "请选择正确的excel文件";
      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 = "导入失败,请选择正确的excel文件";
      return dt;
    }
  }

3. 本地路径读取导入
 

  /// <summary>
  /// 根据文件路径导入excel
  /// </summary>
  /// <param name="filepath"></param>
  /// <param name="errormsg">错误信息</param>
  /// <param name="sheetname">表名，默认取第一张</param>
  /// <returns>可能为null的datatable</returns>
  public static datatable import(string filepath, ref string errormsg, string sheetname = "")
  {
    var exceltype = getexcelfiletype(filepath);
    if (getexcelfiletype(filepath) == null)
    {
      errormsg = "请选择正确的excel文件";
      return null;
    }
    if (!file.exists(filepath))
    {
      errormsg = "没有找到要导入的excel文件";
      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 = "导入失败,请选择正确的excel文件";
    return dt;
  }

4.完整demo

附赠一个winform导入excel的demo。

https://github.com/yimogit/nopiexceldemo