Excel date format using EPPlus

Question

I\'m having trouble with format my cells to Date.

FileInfo info = new FileInfo(path);
using (ExcelPackage package = new ExcelPackage(info))
{
      ExcelWork         


        

Answer 1

var dateColumns = from DataColumn d in dt.Columns
                  where d.DataType == typeof(DateTime) || d.ColumnName.Contains("Date")
                  select d.Ordinal + 1;

foreach (var dc in dateColumns)
{
    worksheet.Cells[2, dc, rowCount + 2, dc].Style.Numberformat.Format = "mm/dd/yyyy hh:mm:ss AM/PM";
}

it will format all the columns with header Date to specific format given/ provided

Answer 2

Following on from the very good Generic solution which takes IEnumerable.. answer we had to go a step further and display different date formatting for different properties. Fro example some columns needed to be displayed as dd/MM/yyyy and others as dd/MM/yyyy hh:mm.

So we added a DisplayFormat annotation with a DataFormatString (representing a DateTime format) to our properties like this:

using System.ComponentModel.DataAnnotations;
...
[DisplayName("Download Date")]
[DisplayFormat(DataFormatString = "dd/MM/yyyy hh:mm")]
public string DownloadDate { get; set; }
...

And then borrowing from Generic solution which takes IEnumerable.. we pulled out the date format string from the DisplayFormat annotation when iterating the properties of the data object:

public void FormatDateColumns(ExcelWorksheet worksheet, IEnumerable<IResult> data)
{
    // Dictionary 'key' contains the Index of the column that contains DateTime data
    // Dictionary 'value' contains the DateTime format for that column
    Dictionary<int, string> dateColumns = new Dictionary<int, string>();
    int dateColumnIndex = 1;

    // find all the DateTime/DateTime? columns in the data object 
    foreach (var PropertyInfo in data.FirstOrDefault().GetType().GetProperties())
    {
        if (PropertyInfo.PropertyType == typeof(DateTime) || PropertyInfo.PropertyType == typeof(DateTime?))
        {
            string dateTimeFormat = Constants.DefaultDateTimeFormat;

            // attempt to get a DataFormatString from a DisplayFormat annotation which may be decorating the Property
            // looking for an annotation something like [DisplayFormat(DataFormatString = "dd-MM-yyyy hh:mm")] 
            if (PropertyInfo.CustomAttributes != null)
            {
                var dislayFormatAttribute = PropertyInfo.CustomAttributes.Where(x => x.AttributeType.Name == "DisplayFormatAttribute").FirstOrDefault();
                if (dislayFormatAttribute != null && dislayFormatAttribute.NamedArguments != null && dislayFormatAttribute.NamedArguments.Count > 0)
                {
                    var displayFormatArg = dislayFormatAttribute.NamedArguments.First();
                    if (displayFormatArg != null && displayFormatArg.TypedValue != null && displayFormatArg.TypedValue.Value != null)
                    {
                        // NOTE: there is probably an easier way to get at this value?
                        dateTimeFormat = displayFormatArg.TypedValue.Value.ToString();
                    }
                }
            }

            dateColumns.Add(dateColumnIndex, dateTimeFormat);
        }
        dateColumnIndex++;
    }

    if (dateColumns.Count > 0)
    {
        // apply the formatting
        dateColumns.ToList().ForEach(item => worksheet.Column(item.Key).Style.Numberformat.Format = item.Value);
    }
}

Answer 3

Some news:

ws.Cells["A3"].Style.Numberformat.Format = "[$-en-US]yyyy-mmm-dd";
ws.Cells["A3"].Formula = "=DATE(2014,10,5)";