C#使用NOPI库实现导入Excel文档

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;
    }
  }

  /// <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;
  }