csvhelper using tuple as records

Question

Can I use tuples when writing to a csv file?

I am trying to reduce memory footprint by using tuple instead of a class instance.

The documentation does mention dynamic and anonymous types; but I don't see for value tuple. Also, how do I handle headers and custom formatting?

Answer 1

You can use WriteRecords with a ValueTuple. You just need to use @dbc's comment and set the MemberTypes in the CsvConfiguration to MemberTypes.Fields.

void Main()
{
    var rows = new (int Id, string Name, DateTime BornOn)[]
    {
        (1, "Jack", new DateTime(2000, 1, 1)),
        (2, "Jill", new DateTime(1990, 3, 13)),
        (3, "McDonald", new DateTime(1970, 5, 12)),
        (4, "Burger King", new DateTime(1880, 8, 22)),
        (5, "Colonel Sanders", new DateTime(1960, 6, 11)),
    };
    
    var config = new CsvConfiguration(CultureInfo.InvariantCulture)
    {
        MemberTypes = CsvHelper.Configuration.MemberTypes.Fields
    };

    //using (var writer = new StreamWriter("path\\to\\file.csv"))
    using (var csv = new CsvWriter(Console.Out, config))
    {
        csv.Context.RegisterClassMap<ValueTupleMap>();
        
        csv.WriteRecords(rows);
    }
}

public class ValueTupleMap : ClassMap<ValueTuple<int,string,DateTime>>
{
    public ValueTupleMap()
    {
        Map(m => m.Item1).Name("#");
        Map(m => m.Item2).Name("Name");
        Map(m => m.Item3).Name("DoB");
    }
}