Question

Uploading a file via web form and parsing its contents to a list how do I allow null or empty value when parsing for C.MN,C.LN, C.Val these three are public datatypes declared like this

Namespace datatypes

       Public class Uploads
  {

        Public long Mn  {get; set;}
        Public int LN     { get;set    }
         Public int Val    {Get;Set}
    }

  List<Uploads> CDU = new List<Uploads>();
                string[] fields;

                string data = read.ReadLine();
                while ((data = read.ReadLine()) != null)
                {
                    if (data.Length != 0)
                    {
                        Uploads C = new Uploads();
                        fields = data.Split(',');
                        C.LN = Convert.ToInt32(fields[0]);
                        C.MN = Convert.ToInt64(fields[1]);                           
                        C.Val = Convert.ToInt32(fields[2]);
                        CDU.Add(C);

Answer 1

Simply put, you have to use nullable value types, e.g.

public class Uploads
{
    public long? Mn { get; set; }
    public int? LN { get; set; }
    public int? Val { get; set; }
}

Of course you’ll need to work out whether to give them a value or leave them as null, presumably based on whether the string is empty or not.

For example:

C.LN = fields[0] == "" ? (int?) null : Convert.ToInt32(fields[0]);

Or just:

if (fields[0] != "")
{
    C.LN = Convert.ToInt32(fields[0]);
}

As an aside, those names are completely unmaintainable. In six months, will you have any idea what they’re meant to mean?