Stream CSV from Web API

stream-csv.cs

[Route("foo/{id}/data/export", Name = nameof(GetCsvData))]
public async Task<HttpResponseMessage> GetCsvData(int id)
{
    var foo = await FooRepository.GetByIdAsync(id);
    if (foo == null)
        return new HttpResponseMessage(HttpStatusCode.NoContent);

    var streamContent = new PushStreamContent(async (stream, content, arg3) =>
    {
        try
        {
            await CsvExporterService.ExportAsync(foo, stream);
        }
        catch (Exception e)
        {
            Log.Write(e);
        }
        finally
        {
            stream.Close();
        }
    });

    return CreateCsvHttpResponseMessage(streamContent);
}

private HttpResponseMessage CreateCsvHttpResponseMessage(HttpContent content)
{
    var response = new HttpResponseMessage { Content = content };
    response.Content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
    response.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment") { FileName = "Export.csv" };
    return response;
}

In this example, the component CsvExporterService writes a CSV string into the given stream using the data based on foo