Question

I have a csv file I am going to read from disk. I do not know up front how many columns or the names of the columns.
Any thoughts on how I should represent the fields. Ideally I want to say something like,

string Val = DataStructure.GetValue(i,ColumnName).
where i is the ith Row.

Oh just as an aside I will be parsing using the TextFieldParser class
http://msdn.microsoft.com/en-us/library/cakac7e6(v=vs.90).aspx

Answer 1

That sounds as if you would need a DataTable which has a Rows and Columns property.

So you can say:

string Val = table.Rows[i].Field<string>(ColumnName);

A DataTable is a table of in-memory data. It can be used strongly typed (as suggested with the Field method) but actually it stores it’s data as objects internally.

You could use this parser to convert the csv to a DataTable.

Edit: I’ve only just seen that you want to use the TextFieldParser. Here’s a possible simple approach to convert a csv to a DataTable:

var table = new DataTable();
using (var parser = new TextFieldParser(File.OpenRead(path)))
{
    parser.Delimiters = new[]{","};
    parser.HasFieldsEnclosedInQuotes = true;
    // load DataColumns from first line 
    String[] headers = parser.ReadFields();
    foreach(var h in headers)
            table.Columns.Add(h);
    // load all other lines as data '
    String[] fields;
    while ((fields = parser.ReadFields()) != null)
    {
        table.Rows.Add().ItemArray = fields;
    }
}