// C# Code

public static class Rfc4180Writer 
{
    public static void WriteDataTable(DataTable sourceTable, TextWriter writer, bool includeHeaders) 
    {
        if (includeHeaders) {
            IEnumerable<String> headerValues = sourceTable.Columns
                .OfType<DataColumn>()
                .Select(column => QuoteValue(column.ColumnName));
                
            writer.WriteLine(String.Join(",", headerValues));
        }

        IEnumerable<String> items = null;

        foreach (DataRow row in sourceTable.Rows) {
            items = row.ItemArray.Select(o => QuoteValue(o.ToString()));
            writer.WriteLine(String.Join(",", items));
        }

        writer.Flush();
    }

    private static string QuoteValue(string value) 
    {
        return String.Concat("\"", 
        value.Replace("\"", "\"\""), "\"");
    }
} 



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// C# Code
public static class Program {
    public static void Main() {
        DataTable sourceTable = new DataTable();

        sourceTable.Columns.AddRange(new DataColumn[] {
            new DataColumn("ID", typeof(Guid)),
            new DataColumn("Date", typeof(DateTime)),
            new DataColumn("StringValue", typeof(string)),
            new DataColumn("NumberValue", typeof(int)),
            new DataColumn("BooleanValue", typeof(bool))
        });

        sourceTable.Rows.Add(Guid.NewGuid(), DateTime.Now, "String1", 100, true);
        sourceTable.Rows.Add(Guid.NewGuid(), DateTime.Now, "String2", 200, false);
        sourceTable.Rows.Add(Guid.NewGuid(), DateTime.Now, "String3", 300, true);

        using (StreamWriter writer = new StreamWriter("C:\\Temp\\dump.csv")) {
            Rfc4180Writer.WriteDataTable(sourceTable, writer, true);
        }
    }
} 

___________________________________________________________________________________________>

For the ASP.NET MVC    

// C# Code
public class ReportController : Controller
{
    [HttpGet()]
    public ActionResult Export()
    {
        DataTable sourceTable = new DataTable();

        sourceTable.Columns.AddRange(new DataColumn[] {
            new DataColumn("ID", typeof(Guid)),
            new DataColumn("Date", typeof(DateTime)),
            new DataColumn("StringValue", typeof(string)),
            new DataColumn("NumberValue", typeof(int)),
            new DataColumn("BooleanValue", typeof(bool))
        });

        sourceTable.Rows.Add(Guid.NewGuid(), DateTime.Now, "String1", 100, true);
        sourceTable.Rows.Add(Guid.NewGuid(), DateTime.Now, "String2", 200, false);
        sourceTable.Rows.Add(Guid.NewGuid(), DateTime.Now, "String3", 300, true);

        byte[] outputBuffer = null;

        using (MemoryStream tempStream = new MemoryStream()) {
            using (StreamWriter writer = new StreamWriter(tempStream)) {
                Rfc4180Writer.WriteDataTable(sourceTable, writer, true);
            }

            outputBuffer = tempStream.ToArray();
        }

        return File(outputBuffer, "text/csv", "export.csv");
    }
} 

Datetable Convert TO CSV