.NET how to output csv from enumeration of anonymous type?

Using FileHelpers, I decorated a class with [DelimitedRecord(",")] and was going to output an enumeration of objects of that type as CSV. But, it didn't work because my class inherits from ActiveRecordLinqBase<T>, which caused some problems.

So, I was wondering if I could just select an enumeration of anonymous types and somehow have filehelpers generate csv from that. I don't like having to define a class just for FileHelpers to output csv.

I would be open to using another csv library, but FileHelpers is proven.

EDIT

@Foovanadil: This would be the sort of thing I am trying to do:

CreateCSV(MyCollection.Select(x=>new{
    x.Prop1,
    x.Prop2,
    x.Prop3
}));

Gives you:

Prop1,Prop2,Prop3
val1a,val2a,val3a
val1b,val2b,val3b
etc.....

Solution

LINQ To CSV worked great for me.

Here's an example of how I am using it:

protected void Page_Load(object sender, EventArgs e)
{
    var courseId = int.Parse(Request["id"]);
    var course = Course.Queryable.Single(x => x.Id == courseId);
    Response.ContentType = "text/csv";
    Response.AddHeader("Content-Disposition", string.Format("attachment;filename=\"{0}.csv\";", course.Code));

    var csvContext = new LINQtoCSV.CsvContext();
    var writer = new System.IO.StreamWriter(Response.OutputStream);
    csvContext.Write(course.Registrations.Select(x => new
    {
        x.StudentId,
        x.Name,
        x.EmailAddress,
        x.MoodleUsername,
        x.Age,
        x.Is65OrOlder,
        x.CertificationAndRank,
        x.Citizenship,
        x.DateOfBirth,
        x.DepartmentName,
        x.StationNumber,        
        x.EmploymentStatus,
        x.HighestEducationLevel
    }), writer);        

    writer.Dispose();
}

UPDATE

There are some downsides to the approach above:

The column order in the csv file is unpredictable. It doesn't follow the order of the property definitions in the anonymous type.
Column headers come from the property names which aren't always what is is desired.

So, I decided I would create a class just for the CSV records, which didn't end up being any more work than the anonymous type did. I used Auto Mapper to flatten my source class and populate the property values of the CSV class. I also decided to compare FileHelpers to Linq To CSV. Linq To CSV was the obvious winner, in my situation:

L2CSV allowed you apply an attribute to each property in the class for defining the column order, column header title, and conversion formats.
FHs would only let you supply a conversion format for each field. The column order depended on the order of the properties as they are defined in the class.
FHs would not infer a column header from the property name nor let you supply one. You could supply a literal string as the header for the CSV file, which is no good: The delimiter is built into the literal string; the column titles' order is not synced with the order of the properties.

I hope these findings are useful. Here is my new code:

// CSV Class

public class CsvRegistration
{
    [CsvColumn(FieldIndex = 0)]
    public string Name { get; set; }

    [CsvColumn(FieldIndex = 1, Name = "Student Id")]
    public int StudentId { get; set; }

    [CsvColumn(FieldIndex = 2, Name = "Email Address")]
    public string EmailAddress { get; set; }

    [CsvColumn(FieldIndex = 3, Name = "Moodle Username")]
    public string MoodleUsername { get; set; }

    [CsvColumn(FieldIndex = 4, Name = "Dept. Name")]
    public string DepartmentName { get; set; }

    [CsvColumn(FieldIndex = 5, Name = "Station #")]
    public string StationNumber { get; set; }

    [CsvColumn(FieldIndex = 6, Name = "Highest Education Level")]
    public string HighestEducationLevel { get; set; }

    [CsvColumn(FieldIndex = 7, Name = "Certification/Rank")]
    public string CertificationAndRank { get; set; }

    [CsvColumn(FieldIndex = 8, Name = "Employment Status")]
    public string EmploymentStatus { get; set; }

    [CsvColumn(FieldIndex = 9, Name = "Registration Date")]
    public DateTime RegistrationDate { get; set; }

    [CsvColumn(FieldIndex = 10, Name = "Date of Birth")]
    public DateTime DateOfBirth { get; set; }

    [CsvColumn(FieldIndex = 11)]
    public int Age { get; set; }

    [CsvColumn(FieldIndex = 12)]
    public string Citizenship { get; set; }

    [CsvColumn(FieldIndex = 13)]
    public string Race { get; set; }

    [CsvColumn(FieldIndex = 14)]
    public string Ethnicity { get; set; }

    [CsvColumn(FieldIndex = 15, Name = "Home Address")]
    public string HomeAddressLine1 { get; set; }

    [CsvColumn(FieldIndex = 16, Name = "City")]
    public string HomeAddressCity { get; set; }

    [CsvColumn(FieldIndex = 17, Name = "State")]
    public string HomeAddressState { get; set; }

    [CsvColumn(FieldIndex = 18, Name = "Zip")]
    public string HomeAddressZip { get; set; }

    [CsvColumn(FieldIndex = 19, Name = "County")]
    public string HomeAddressCounty { get; set; }

    [CsvColumn(FieldIndex = 20, Name = "Home Phone")]
    public string HomePhone { get; set; }

    [CsvColumn(FieldIndex = 21, Name = "Work Phone")]
    public string WorkPhone { get; set; }
}


// ASPX page to serve csv file

protected void Page_Load(object sender, EventArgs e)
{
    var courseId = int.Parse(Request["id"]);
    var course = Course.Queryable.Single(x => x.Id == courseId);
    Response.ContentType = "text/csv";
    Response.AddHeader("Content-Disposition", string.Format("attachment;filename=\"{0}.csv\";", course.Code));

    using (var writer = new System.IO.StreamWriter(Response.OutputStream))
    {
        var registrations = Mapper.Map<IEnumerable<Registration>, IEnumerable<CsvRegistration>>(course.Registrations);
        var cc = new LINQtoCSV.CsvContext();
        cc.Write(registrations, writer);
    }
}