CsvHelper Attributes

Data Annotations are attributes which are applied to the class or members that specify validation rules, specify how the data is displayed, etc .

CsvHelper allows you to configure most of the configuration which we have done using class maps can also be done using data annotations attributes.

Let's consider the following class maps.

private class Book
{
    public int Id { get; set; }
    public string Title { get; set; }
    public int NoOfPages { get; set; }
}

public sealed class BookMap : ClassMap<Book>
{
    public BookMap()
    {
        Map(m => m.Id).Name("BookId");
        Map(m => m.Title);
        Map(m => m.NoOfPages).Name("Pages");
    }
}

Now using the data annotation attributes, you can achieve the above configuration as shown below.

private class Book
{
    [Name("BookId")]
    public int Id { get; set; }
    public string Title { get; set; }

    [Name("Pages")]
    public int NoOfPages { get; set; }
}

The following example shows some more attributes.

public class Book
{
    [Index(0)]
    public int Id { get; set; }

    [Index(1)]
    public string Title { get; set; }

    [BooleanTrueValues("yes")]
    [BooleanFalseValues("no")]
    public bool IsFree { get; set; }

    [Optional]
    public string Description { get; set; }

    [Ignore]
    public string TOC { get; set; }
}