似乎未为日期设置 cell.DataType。
这样做的方法是查看单元格是否具有 StyleIndex，它是文档中单元格格式数组的索引。
然后，您使用 cellFormat.NumberFormatId 来查看这是否是日期数据类型。
这是一些代码：
public class ExcelCellWithType
{
public string Value { get; set; }
public UInt32Value ExcelCellFormat { get; set; }
public bool IsDateTimeType { get; set; }
}
public class ExcelDocumentData
{
public ExcelXmlStatus Status { get; set; }
public IList<Sheet> Sheets { get; set; }
public IList<ExcelSheetData> SheetData { get; set; }
public ExcelDocumentData()
{
Status = new ExcelXmlStatus();
Sheets = new List<Sheet>();
SheetData = new List<ExcelSheetData>();
}
}
...
public ExcelDocumentData ReadSpreadSheetDocument(SpreadsheetDocument mySpreadsheet, ExcelDocumentData data)
{
var workbookPart = mySpreadsheet.WorkbookPart;
data.Sheets = workbookPart.Workbook.Descendants<Sheet>().ToList();
foreach (var sheet in data.Sheets)
{
var sheetData = new ExcelSheetData { SheetName = sheet.Name };
var workSheet = ((WorksheetPart)workbookPart.GetPartById(sheet.Id)).Worksheet;
sheetData.ColumnConfigurations = workSheet.Descendants<Columns>().FirstOrDefault();
var rows = workSheet.Elements<SheetData>().First().Elements<Row>().ToList();
if (rows.Count > 1)
{
foreach (var row in rows)
{
var dataRow = new List<ExcelCellWithType>();
var cellEnumerator = GetExcelCellEnumerator(row);
while (cellEnumerator.MoveNext())
{
var cell = cellEnumerator.Current;
var cellWithType = ReadExcelCell(cell, workbookPart);
dataRow.Add(cellWithType);
}
sheetData.DataRows.Add(dataRow);
}
}
data.SheetData.Add(sheetData);
}
return data;
}
...
private ExcelCellWithType ReadExcelCell(Cell cell, WorkbookPart workbookPart)
{
var cellValue = cell.CellValue;
var text = (cellValue == null) ? cell.InnerText : cellValue.Text;
if (cell.DataType?.Value == CellValues.SharedString)
{
text = workbookPart.SharedStringTablePart.SharedStringTable
.Elements<SharedStringItem>().ElementAt(
Convert.ToInt32(cell.CellValue.Text)).InnerText;
}
var cellText = (text ?? string.Empty).Trim();
var cellWithType = new ExcelCellWithType();
if (cell.StyleIndex != null)
{
var cellFormat = workbookPart.WorkbookStylesPart.Stylesheet.CellFormats.ChildElements[
int.Parse(cell.StyleIndex.InnerText)] as CellFormat;
if (cellFormat != null)
{
cellWithType.ExcelCellFormat = cellFormat.NumberFormatId;
var dateFormat = GetDateTimeFormat(cellFormat.NumberFormatId);
if (!string.IsNullOrEmpty(dateFormat))
{
cellWithType.IsDateTimeType = true;
if (!string.IsNullOrEmpty(cellText))
{
if (double.TryParse(cellText, out var cellDouble))
{
var theDate = DateTime.FromOADate(cellDouble);
cellText = theDate.ToString(dateFormat);
}
}
}
}
}
cellWithType.Value = cellText;
return cellWithType;
}
//// https://msdn.microsoft.com/en-GB/library/documentformat.openxml.spreadsheet.numberingformat(v=office.14).aspx
private readonly Dictionary<uint, string> DateFormatDictionary = new Dictionary<uint, string>()
{
[14] = "dd/MM/yyyy",
[15] = "d-MMM-yy",
[16] = "d-MMM",
[17] = "MMM-yy",
[18] = "h:mm AM/PM",
[19] = "h:mm:ss AM/PM",
[20] = "h:mm",
[21] = "h:mm:ss",
[22] = "M/d/yy h:mm",
[30] = "M/d/yy",
[34] = "yyyy-MM-dd",
[45] = "mm:ss",
[46] = "[h]:mm:ss",
[47] = "mmss.0",
[51] = "MM-dd",
[52] = "yyyy-MM-dd",
[53] = "yyyy-MM-dd",
[55] = "yyyy-MM-dd",
[56] = "yyyy-MM-dd",
[58] = "MM-dd",
[165] = "M/d/yy",
[166] = "dd MMMM yyyy",
[167] = "dd/MM/yyyy",
[168] = "dd/MM/yy",
[169] = "d.M.yy",
[170] = "yyyy-MM-dd",
[171] = "dd MMMM yyyy",
[172] = "d MMMM yyyy",
[173] = "M/d",
[174] = "M/d/yy",
[175] = "MM/dd/yy",
[176] = "d-MMM",
[177] = "d-MMM-yy",
[178] = "dd-MMM-yy",
[179] = "MMM-yy",
[180] = "MMMM-yy",
[181] = "MMMM d, yyyy",
[182] = "M/d/yy hh:mm t",
[183] = "M/d/y HH:mm",
[184] = "MMM",
[185] = "MMM-dd",
[186] = "M/d/yyyy",
[187] = "d-MMM-yyyy"
};
private string GetDateTimeFormat(UInt32Value numberFormatId)
{
return DateFormatDictionary.ContainsKey(numberFormatId) ? DateFormatDictionary[numberFormatId] : string.Empty;
}