在Excel电子表格中写入日期会导致无法读取的内容

SheetData.AppendChild(new Row(
    new Cell() 
    { 
        // CellValue is set to OADate because that's what Excel expects.
        CellValue = new CellValue(date.ToOADate().ToString(CultureInfo.InvariantCulture)), 
        // Style index set to style (0 based).
        StyleIndex = 0
    }));

注意:Office 2010和2013 可以处理日期不同，但默认情况下似乎没有。

他们支持ISO 8601格式的日期，即yyyy-MM-ddTHH:mm:ss，正好这也是标准格式可排序("s")，所以你可以这样做:

SheetData.AppendChild(new Row(
    new Cell() 
    { 
        CellValue = new CellValue(date.ToString("s")), 
        // This time we do add the DataType attribute but ONLY for Office 2010+.
        DataType = CellValues.Date
        StyleIndex = 1
    }));

<row>
  <c s="0" t="d">
    <v>2015-08-05T11:13:57</v>
  </c>
</row>

完整代码清单

下面是添加具有日期格式的单元格所需的最小代码示例。

private static void TestExcel()
{
    using (var Spreadsheet = SpreadsheetDocument.Create("C:''Example.xlsx", SpreadsheetDocumentType.Workbook))
    {
        // Create workbook.
        var WorkbookPart = Spreadsheet.AddWorkbookPart();
        var Workbook = WorkbookPart.Workbook = new Workbook();
        // Add Stylesheet.
        var WorkbookStylesPart = WorkbookPart.AddNewPart<WorkbookStylesPart>();
        WorkbookStylesPart.Stylesheet = GetStylesheet();
        WorkbookStylesPart.Stylesheet.Save();
        // Create worksheet.
        var WorksheetPart = Spreadsheet.WorkbookPart.AddNewPart<WorksheetPart>();
        var Worksheet = WorksheetPart.Worksheet = new Worksheet();
        // Add data to worksheet.
        var SheetData = Worksheet.AppendChild(new SheetData());
        SheetData.AppendChild(new Row(
            new Cell() { CellValue = new CellValue(DateTime.Today.ToOADate().ToString(CultureInfo.InvariantCulture)), StyleIndex = 1 },
            // Only works for Office 2010+.
            new Cell() { CellValue = new CellValue(DateTime.Today.ToString("s")), DataType = CellValues.Date, StyleIndex = 1 }));
        // Link worksheet to workbook.
        var Sheets = Workbook.AppendChild(new Sheets());
        Sheets.AppendChild(new Sheet()
        {
            Id = WorkbookPart.GetIdOfPart(WorksheetPart),
            SheetId = (uint)(Sheets.Count() + 1),
            Name = "Example"
        });
        Workbook.Save();
    }
}
private static Stylesheet GetStylesheet()
{
    var StyleSheet = new Stylesheet();
     // Create "fonts" node.
    var Fonts = new Fonts();
    Fonts.Append(new Font()
    {
        FontName = new FontName() { Val = "Calibri" },
        FontSize = new FontSize() { Val = 11 },
        FontFamilyNumbering = new FontFamilyNumbering() { Val = 2 },
    });
    Fonts.Count = (uint)Fonts.ChildElements.Count;
    // Create "fills" node.
    var Fills = new Fills();
    Fills.Append(new Fill()
    {
        PatternFill = new PatternFill() { PatternType = PatternValues.None }
        });
        Fills.Append(new Fill()
        {
            PatternFill = new PatternFill() { PatternType = PatternValues.Gray125 }
        });
    Fills.Count = (uint)Fills.ChildElements.Count;
    // Create "borders" node.
    var Borders = new Borders();
    Borders.Append(new Border()
    {
        LeftBorder = new LeftBorder(),
        RightBorder = new RightBorder(),
        TopBorder = new TopBorder(),
        BottomBorder = new BottomBorder(),
        DiagonalBorder = new DiagonalBorder()
    });
    Borders.Count = (uint)Borders.ChildElements.Count;
    // Create "cellStyleXfs" node.
    var CellStyleFormats = new CellStyleFormats();
    CellStyleFormats.Append(new CellFormat()
    {
        NumberFormatId = 0,
        FontId = 0,
        FillId = 0,
        BorderId = 0
    });
    CellStyleFormats.Count = (uint)CellStyleFormats.ChildElements.Count;
    // Create "cellXfs" node.
    var CellFormats = new CellFormats();
    // A default style that works for everything but DateTime
    CellFormats.Append(new CellFormat()
    {
        BorderId = 0,
        FillId = 0,
        FontId = 0,
        NumberFormatId = 0,
        FormatId = 0,
        ApplyNumberFormat = true
    });
   // A style that works for DateTime (just the date)
   CellFormats.Append(new CellFormat()
    {
        BorderId = 0,
        FillId = 0,
        FontId = 0,
        NumberFormatId = 14, // or 22 to include the time
        FormatId = 0,
        ApplyNumberFormat = true
    });
    CellFormats.Count = (uint)CellFormats.ChildElements.Count;
    // Create "cellStyles" node.
    var CellStyles = new CellStyles();
    CellStyles.Append(new CellStyle()
    {
        Name = "Normal",
        FormatId = 0,
        BuiltinId = 0
    });
    CellStyles.Count = (uint)CellStyles.ChildElements.Count;
    // Append all nodes in order.
    StyleSheet.Append(Fonts);
    StyleSheet.Append(Fills);
    StyleSheet.Append(Borders);
    StyleSheet.Append(CellStyleFormats);
    StyleSheet.Append(CellFormats);
    StyleSheet.Append(CellStyles);
    return StyleSheet;
}