In ASP.NET Core-6 Web API, I am implementing Excel File upload using EPPLUS Excel Package.

I have this model:

public class LeaveApplication
{
    public Guid Id { get; set; }
    public string EmployeeId { get; set; }
    public DateTime StartDate { get; set; }
    public DateTime EndDate { get; set; }
    public LeaveType? LeaveType { get; set; }   
}

EnumList:

public class EnumList
{
    public enum LeaveType : byte
    {
        Annual = 1,
        Casual = 2,
        Compassionate = 3,
        Maternity = 4
    }
}

So I have this method for the Excel upload.

public async Task<List<LeaveApplication>> Import(IFormFile file)
{
    var list = new List<LeaveApplication>();
    using (var stream = new MemoryStream())
    {
        await file.CopyToAsync(stream);
        using (var package = new ExcelPackage(stream))
        {

            ExcelWorksheet worksheet = package.Workbook.Worksheets[0];
            var rowcount = worksheet.Dimension.Rows;
            var colcount = worksheet.Dimension.Columns;

            for (int row = 2; row < rowcount; row  )
            {
                list.Add(new LeaveApplication {
                    EmployeeId = worksheet.Cells[row,1].Value.ToString().Trim(),
                    StartDate = DateTime.Parse(worksheet.Cells[row, 2].Value.ToString()),
                    EndDate = DateTime.Parse(worksheet.Cells[row, 3].Value.ToString()),
                    LeaveType = byte.Parse(worksheet.Cells[row, 4].Value.ToString())
                });
            }
        }
    }
    _dbContext.LeaveApplications.AddRange(list);
    await _dbContext.SaveChangesAsync();

    return list;
}

I got this error:

Cannot implicitly convert type 'byte' to 'EnumList.LeaveType?'. An explicit conversion exists (are you missing a cast?)

Then this line of code is highlighted:

LeaveType = byte.Parse(worksheet.Cells[row, 4].Value.ToString())

How do I get this resolved?

Thanks

CodePudding user response：

Explicit cast from byte to EnumList.LeaveType.

LeaveType = String.IsNullOrEmpty(worksheet.Cells[row, 4].Value.ToString())
    ? (EnumList.LeaveType?)null
    : (EnumList.LeaveType)byte.Parse(worksheet.Cells[row, 4].Value.ToString())

Or you can work with parsing from string to EnumList.LeaveType:

LeaveType = String.IsNullOrEmpty(worksheet.Cells[row, 4].Value.ToString())
    ? (EnumList.LeaveType?)null
    : Enum.Parse(typeof(EnumList.LeaveType), worksheet.Cells[row, 4].Value.ToString())

Demo @ .NET Fiddle

Will recommend using Enum.TryParse() to avoid the exception due to an invalid value for the enum.