Extension Methods for Generating CSV strings from objects (C# 3.0)

CSVExtensions.cs

using System;

public static class CSVExtensions
{
	public static string ToCSV(this DataTable dt)
	{
		string output = string.Empty;
		string tmp;
		char[] special = new char[] { '"', '\n', '\r', ',' };
		// loop through all columns
		for (int i = 0; i < dt.Columns.Count; i++)
		{
			output += "\"" + dt.Columns[i].ColumnName + "\"";
			// if last column, add \r\n, otherwise ,
			output += (dt.Columns.Count == (i + 1)) ? "\r\n" : ",";
		}
		foreach (DataRow dr in dt.Rows)
		{
			for (int i = 0; i < dt.Columns.Count; i++)
			{
				tmp = dr[i].ToString();
				// if there are any special characters, wrap in "
				if (tmp.IndexOfAny(special) > 0)
				{
					// replace " with ""
					// replace \r\n or \r with \n
					tmp = tmp.Replace("\"", "\"\"").Replace("\r\n", "\n").Replace('\r', '\n');
					tmp = "\"" + tmp + "\"";
				}
				
				output += tmp;
				
				// if last column, add \r\n, otherwise ,
				output += (dt.Columns.Count == (i + 1)) ? "\r\n" : ",";
			}
		}
		return output;
	}
}