OpenXML SDK：如何识别单元格的数据类型？

Question

我正在使用OPenXML SDK来与excel一起工作。目前，我面临着一个问题，如何识别单元格的数据类型，日期时间或数字。因为，如果单元格的类型是日期，我们需要再次将double值转换为datetime。

Answer 1

基于信息我已经从我写了下面的代码应该回答你的问题

public class ExcelEngine : IExcelEngine 
{ 
    private readonly SpreadsheetDocument _wb; 
    private WorkbookPart _wbp; 
    private SharedStringTablePart _sstp; 

    // Used to cache the lookup of worksheet parts 
    private Dictionary<string, WorksheetPart> _wsParts = new Dictionary<string, WorksheetPart>(); 

    #region Constructors 

    public ExcelEngine(Stream stream) 
    { 
     Contracts.IsNotNull(stream); 

     _wb = SpreadsheetDocument.Open(stream, false); 
     Initialise(); 
    } 

    public ExcelEngine(string fileName) 
    { 
     Contracts.IsNullOrWhiteSpace(fileName); 

     _wb = SpreadsheetDocument.Open(fileName, false); 
     Initialise(); 
    } 

    #endregion 

    #region IExcelEngine 

    /// <summary> 
    /// Get the list of sheet names from the spreadsheet 
    /// </summary> 
    /// <returns></returns> 
    public IList<string> GetSheetNames() 
    { 
     return _wbp.Workbook 
      .Descendants<Sheet>() 
      .Select(s => s.Name.Value) 
      .ToList<String>(); 
    } 

    /// <summary> 
    /// Given a sheet name and a cell reference, return the contents of the cell 
    /// </summary> 
    /// <param name="sheetName"></param> 
    /// <param name="addressName"></param> 
    /// <returns></returns>   
    public string GetCellValue(string sheetName, string addressName) 
    { 
     return GetCellValueLocal(sheetName, addressName); 
    } 


    /// <summary> 
    /// Given a sheet name and a cell reference, return the contents of the cell as a boolean value 
    /// </summary> 
    /// <param name="sheetName"></param> 
    /// <param name="addressName"></param> 
    /// <returns></returns> 
    public bool GetCellBool(string sheetName, string addressName) 
    { 
     var value = GetCellValueLocal(sheetName, addressName); 

     bool result; 
     bool.TryParse(value, out result); 

     return result; 
    } 

    #endregion 

    #region Private Methods 

    private void Initialise() 
    { 
     _wbp = _wb.WorkbookPart; 
     _sstp = _wbp.GetPartsOfType<SharedStringTablePart>().First(); 
    } 


    private string GetCellValueLocal(string sheetName, string addressName) 
    { 
     string value = null; 

     WorksheetPart wsPart = GetWorkSheetPart(sheetName); 

     // Use its Worksheet property to get a reference to the cell 
     // whose address matches the address you supplied. 
     Cell cell = wsPart.Worksheet.Descendants<Cell>(). 
      Where(c => c.CellReference == addressName).FirstOrDefault(); 

     if (cell != null) 
     { 
      value = cell.InnerText; 

      if (cell.DataType != null) 
       switch (cell.DataType.Value) 
       { 
        case CellValues.SharedString: 
         int ssid = int.Parse(cell.CellValue.Text); 
         value = _sstp.SharedStringTable.ElementAt(ssid).InnerText; 
         break; 

        case CellValues.Boolean: 
         switch (value) 
         { 
          case "0": 
           value = "FALSE"; 
           break; 
          default: 
           value = "TRUE"; 
           break; 
         } 
         break; 

        case CellValues.Date: 
         break; 

        case CellValues.String: 
         break; 
       } 
      Debug.WriteLine($"Cell {cell.CellReference}: '{value}'"); 
     } 

     return value; 
    } 

    private WorksheetPart GetWorkSheetPart(string sheetName) 
    { 
     // Does it exist in the cache? If not, load it 
     if (!_wsParts.ContainsKey(sheetName)) 
     { 
      // Find the sheet with the supplied name, and then use that 
      // Sheet object to retrieve a reference to the first worksheet. 
      Sheet theSheet = _wbp.Workbook.Descendants<Sheet>() 
       .Where(s => s.Name == sheetName) 
       .FirstOrDefault(); 

      // If not sheet throw an exception 
      if (theSheet == null) 
       throw new ArgumentException($"Sheet {sheetName} not found in workbook"); 

      // Retrieve a reference to the worksheet part. 
      _wsParts.Add(sheetName, (WorksheetPart) (_wbp.GetPartById(theSheet.Id))); 
     } 

     return _wsParts[sheetName]; 
    } 

    #endregion 

    public void Dispose() 
    { 
     _wb.Close(); 
     _wb.Dispose(); 
    } 
}