Using Service Stack to create a CSV file with ASP.NET Webforms

Recently I needed to export some data from a CMS (Content Management System). The customer requested that the data be in CSV format. There are a lot of different ways to do this, but this one might be one of the easiest!

CSV isn’t a terribly complicated format, but people do screw it up often enough. We could write some simple code to output our data in CSV format, but why not stand on the shoulders of giants? We’ll leverage Service Stack to do all the heavy lifting for us.

Here is a snippet from my code. This is a sample click event handler in ASP.NET Webforms:

protected void uxExportProducts_Click(object sender, EventArgs e)
{
    Response.Clear();
    Response.ContentType = "text/csv";
    Response.AddHeader("Content-Disposition", "attachment; filename=product-export.csv");

    CsvSerializer.SerializeToStream(GetProducts(), Response.OutputStream);
    Response.End();
}

To setup, we need to clear any other headers that may have been set, set the content type, and “force” a file download with the “Content-Disposition” header. Make sure you update your code to set the appropriate filename. After that we just need to serialize out the data, and then End() the response so the rest of the page doesn’t automatically render.

So what does the GetProducts() method do? Here is the method signature for the Serialization method:

public static string SerializeToCsv<T>(IEnumerable<T> records);

I simply had my data layer return a List<ProductData> (or it could be a IEnumerable<T>):

public List<ProductData> GetProducts()
{
    // Code to get the data from the DB or web service or whatever...
}

…and ProductData is just a POCO:

public class ProductData
{
    public string ProductName { get; set; }
    public string Photo { get; set; }
    public string Description { get; set; }
    public string Category { get; set; }
}

Hope that helps someone!