CustomFormatUsageDemo

internal class Program
{
    static void Main(string[] args)
    {
        EdmEntityType customer = new EdmEntityType("ns", "customer");
        var key = customer.AddStructuralProperty("Id", EdmPrimitiveTypeKind.Int32);
        customer.AddKeys(key);
        customer.AddStructuralProperty("Name", EdmPrimitiveTypeKind.String);

        ODataEntry entry1 = new ODataEntry()
        {
            Properties = new[]
            {
                new ODataProperty(){Name = "Id", Value = 51}, 
                new ODataProperty(){Name = "Name", Value = "Name_A"}, 
            }
        };

        ODataEntry entry2 = new ODataEntry()
        {
            Properties = new[]
            {
                new ODataProperty(){Name = "Id", Value = 52}, 
                new ODataProperty(){Name = "Name", Value = "Name_B"}, 
            }
        };

        var stream = new MemoryStream();
        var message = new Message { Stream = stream };

        // Set Content-Type header value
        message.SetHeader("Content-Type", "text/csv");

        var settings = new ODataMessageWriterSettings
        {
            // Set our resolver here.
            MediaTypeResolver = CsvMediaTypeResolver.Instance,
            DisableMessageStreamDisposal = true,
        };

        using (var messageWriter = new ODataMessageWriter(message, settings))
        {
            var writer = messageWriter.CreateODataFeedWriter(null, customer);
            writer.WriteStart(new ODataFeed());
            writer.WriteStart(entry1);
            writer.WriteEnd();
            writer.WriteStart(entry2);
            writer.WriteEnd();
            writer.WriteEnd();
            writer.Flush();
        }

        stream.Seek(0, SeekOrigin.Begin);
        string msg;

        using (var sr = new StreamReader(stream)) { msg = sr.ReadToEnd(); }
        Console.WriteLine(msg);
    }
}

internal class Message : IODataResponseMessage, IDisposable
{
    private readonly Dictionary<string, string> headers = new Dictionary<string, string>();
    public IEnumerable<KeyValuePair<string, string>> Headers { get { return this.headers; } }
    public int StatusCode { get; set; }
    public Uri Url { get; set; }
    public string Method { get; set; }
    public Stream Stream { get; set; }
    public Action DisposeAction { get; set; }
    
    public string GetHeader(string headerName)
    {
        string headerValue;
        return this.headers.TryGetValue(headerName, out headerValue) ? headerValue : null;
    }

    public void SetHeader(string headerName, string headerValue)
    {
        headers[headerName] = headerValue;
    }

    public Stream GetStream()
    {
        return this.Stream;
    }

    void IDisposable.Dispose()
    {
        if (this.DisposeAction != null)
        {
            this.DisposeAction();
        }
    }
}