CsvHelper Write CSV File

CsvHelper allows you to write data to the file in a CSV format very easily. First, we need to create a list of class objects that we want to write to a CSV file. To do so, let's create a new class Author.

public class Author
{
    public int AuthorId { get; set; }
    public string Name { get; set; }
}

The following example first creates a list of authors and then writes all the authors' data to the CSV file.

public static void Example1()
{
    var authors = new List<Author>
    {
        new Author { AuthorId = 1, Name="Carson Alexander" },
        new Author { AuthorId = 2, Name="Meredith Alonso" },
        new Author { AuthorId = 3, Name="Arturo Anand" },
        new Author { AuthorId = 4, Name="Gytis Barzdukas"},
        new Author { AuthorId = 5, Name="Yan Li" },
    };

    using (var writer = new StreamWriter(@"D:\mycsvfile.csv"))
    using (var csv = new CsvWriter(writer, CultureInfo.InvariantCulture))
    {
        csv.WriteRecords(authors);
    }
}

When you execute the above example, you will see that the CSV file is created which contains the following data.

AuthorId,Name
1,Carson Alexander
2,Meredith Alonso
3,Arturo Anand
4,Gytis Barzdukas
5,Yan Li

CsvHelper allows you to write all the data from dynamic objects instead of using concrete class objects.

public static void Example2()
{
    dynamic author1 = new ExpandoObject();
    author1.AuthorId = 1;
    author1.Name = "Carson Alexander";

    dynamic author2 = new ExpandoObject();
    author2.AuthorId = 2;
    author2.Name = "Meredith Alonso";

    dynamic author3 = new ExpandoObject();
    author3.AuthorId = 3;
    author3.Name = "Arturo Anand";

    var authors = new List<dynamic>()
    {
        author1,
        author2,
        author3
    };

    using (var writer = new StreamWriter(@"D:\mycsvfile.csv"))
    using (var csv = new CsvWriter(writer, CultureInfo.InvariantCulture))
    {
        csv.WriteRecords(authors);
    }
}

You can also write CSV rows from anonymous-type objects as shown below.

public static void Example3()
{
    var authors = new List<object>
    {
        new { AuthorId = 1, Name="Carson Alexander" },
        new { AuthorId = 2, Name="Meredith Alonso" },
        new { AuthorId = 3, Name="Arturo Anand" },
        new { AuthorId = 4, Name="Gytis Barzdukas"},
        new { AuthorId = 5, Name="Yan Li" },
    };

    using (var writer = new StreamWriter(@"D:\mycsvfile.csv"))
    using (var csv = new CsvWriter(writer, CultureInfo.InvariantCulture))
    {
        csv.WriteRecords(authors);
    }
}