"m/d/yyyy h:mm tt" [AM/PM] 是否有 OpenXml (C#) date/time 格式？

Is there an OpenXml (C#) date/time format for "m/d/yyyy h:mm tt" [AM/PM]?

查看列表here，您可以看到：

你可以看到大多数案例似乎都涵盖了，22个已经很接近了，但我真正需要的是m/d/yyyyh:mm tt - 有谁知道在 OpenXml 中设置它的方法吗？谢谢。

没有内置格式来实现您在 OpenXml 中所追求的，但您可以轻松添加自己的格式。您需要的格式字符串是 m/d/yyyy\ h:mm\ AM/PM.

为了应用格式，您需要创建一个 NumberingFormats object, add a NumberingFormat to it and assign it to the NumberingFormats property on a Stylesheet。以下方法将创建 Stylesheet 格式为 m/d/yyyy\ h:mm\ AM/PM：

private static Stylesheet CreateStyles()
{
    Stylesheet styleSheet = new Stylesheet();

    NumberingFormats nfs = new NumberingFormats();

    NumberingFormat nf;
    nf = new NumberingFormat();
    nf.NumberFormatId = 165;
    nf.FormatCode = "m/d/yyyy\ h:mm\ AM/PM";
    nfs.Append(nf);

    CellFormat cf = new CellFormat();
    cf.NumberFormatId = nf.NumberFormatId;
    cf.ApplyNumberFormat = true;

    CellFormats cfs = new CellFormats();
    cfs.Append(cf);
    styleSheet.CellFormats = cfs;
    styleSheet.NumberingFormats = nfs;
    styleSheet.Borders = new Borders();
    styleSheet.Borders.Append(new Border());
    styleSheet.Fills = new Fills();
    styleSheet.Fills.Append(new Fill());
    styleSheet.Fonts = new Fonts();
    styleSheet.Fonts.Append(new Font());

    CellStyles css = new CellStyles();
    CellStyle cs = new CellStyle();
    cs.FormatId = 0;
    cs.BuiltinId = 0;
    css.Append(cs);
    css.Count = UInt32Value.FromUInt32((uint)css.ChildElements.Count);
    styleSheet.Append(css);
    return styleSheet;
}

以下代码将使用上面添加的格式从头开始创建一个包含 2 个日期（在 A1 和 B1 中）的新文件：

public static void CreateFile(string filename)
{
    using (SpreadsheetDocument spreadsheetDocument = 
        SpreadsheetDocument.Create(filename, SpreadsheetDocumentType.Workbook))
    {
        // Add a WorkbookPart to the document.
        WorkbookPart workbookpart = spreadsheetDocument.AddWorkbookPart();
        workbookpart.Workbook = new Workbook();
        workbookpart.AddNewPart<WorkbookStylesPart>();

        // Add a WorksheetPart to the WorkbookPart.
        WorksheetPart worksheetPart = workbookpart.AddNewPart<WorksheetPart>();
        worksheetPart.Worksheet = new Worksheet(new SheetData());

        // Add Sheets to the Workbook.
        Sheets sheets = spreadsheetDocument.WorkbookPart.Workbook.AppendChild<Sheets>(new Sheets());

        // Append a new worksheet and associate it with the workbook.
        Sheet sheet = new Sheet()
        {
            Id = spreadsheetDocument.WorkbookPart.GetIdOfPart(worksheetPart),
            SheetId = 1,
            Name = "Sheet 1"
        };
        sheets.Append(sheet);
        Worksheet worksheet = new Worksheet();
        SheetData sheetData = new SheetData();

        Stylesheet styleSheet = CreateStyles();
        Row row = CreateRow();

        sheetData.Append(row);
        worksheet.Append(sheetData);
        worksheetPart.Worksheet = worksheet;
        workbookpart.WorkbookStylesPart.Stylesheet = styleSheet;

        // Close the document.
        spreadsheetDocument.Close();
    }
}

private static Row CreateRow()
{
    Row row = new Row();

    DateTime now = DateTime.UtcNow;
    //add a date cell using the number data type
    Cell cell = new Cell();
    cell.StyleIndex = 0;
    cell.DataType = CellValues.Number;
    string columnValue = now.ToOADate().ToString();
    cell.CellValue = new CellValue(columnValue);
    row.Append(cell);

    //add a date cell using the date data type
    Cell cell2 = new Cell();
    cell2.StyleIndex = 0;
    cell2.DataType = CellValues.Date;
    columnValue = now.ToString("o");
    cell2.CellValue = new CellValue(columnValue);
    row.Append(cell2);
    return row;
}

原始答案（基于带有 AM/PM 说明符的 24 小时制）

很遗憾，我认为这是不可能的。

您可以定义自定义格式但是规范的部分18.8.31 numFmts指出：

If the format contains AM or PM, the hour is based on the 12-hour clock, where "AM" or "A" indicates times from midnight until noon and "PM" or "P" indicates times from noon until midnight. Otherwise, the hour is based on the 24-hour clock.

因此，不能将 24 小时格式与 AM/PM 后缀混合使用。