Simple C# CSV Excel export class
- by Chris
Thought this might be handy for someone, this is an extremely simple CSV export class that I needed. Features:
Extremely simple to use
Escapes commas and quotes so excel handles them fine
Exports date and datetimes in timezone-proof format
Without further ado:
using System;
using System.Data.SqlTypes;
using System.IO;
using System.Text;
using System.Collections.Generic;
/// <summary>
/// Simple CSV export
/// Example:
/// CsvExport myExport = new CsvExport();
///
/// myExport.AddRow();
/// myExport["Region"] = "New York, USA";
/// myExport["Sales"] = 100000;
/// myExport["Date Opened"] = new DateTime(2003, 12, 31);
///
/// myExport.AddRow();
/// myExport["Region"] = "Sydney \"in\" Australia";
/// myExport["Sales"] = 50000;
/// myExport["Date Opened"] = new DateTime(2005, 1, 1, 9, 30, 0);
///
/// Then you can do any of the following three output options:
/// string myCsv = myExport.Export();
/// myExport.ExportToFile("Somefile.csv");
/// byte[] myCsvData = myExport.ExportToBytes();
/// </summary>
public class CsvExport
{
/// <summary>
/// To keep the ordered list of column names
/// </summary>
List<string> fields = new List<string>();
/// <summary>
/// The list of rows
/// </summary>
List<Dictionary<string, object>> rows = new List<Dictionary<string, object>>();
/// <summary>
/// The current row
/// </summary>
Dictionary<string, object> currentRow { get { return rows[rows.Count - 1]; } }
/// <summary>
/// Set a value on this column
/// </summary>
public object this[string field]
{
set
{
// Keep track of the field names, because the dictionary loses the ordering
if (!fields.Contains(field)) fields.Add(field);
currentRow[field] = value;
}
}
/// <summary>
/// Call this before setting any fields on a row
/// </summary>
public void AddRow()
{
rows.Add(new Dictionary<string, object>());
}
/// <summary>
/// Converts a value to how it should output in a csv file
/// If it has a comma, it needs surrounding with double quotes
/// Eg Sydney, Australia -> "Sydney, Australia"
/// Also if it contains any double quotes ("), then they need to be replaced with quad quotes[sic] ("")
/// Eg "Dangerous Dan" McGrew -> """Dangerous Dan"" McGrew"
/// </summary>
string MakeValueCsvFriendly(object value)
{
if (value == null) return "";
if (value is INullable && ((INullable)value).IsNull) return "";
if (value is DateTime)
{
if (((DateTime)value).TimeOfDay.TotalSeconds==0)
return ((DateTime)value).ToString("yyyy-MM-dd");
return ((DateTime)value).ToString("yyyy-MM-dd HH:mm:ss");
}
string output = value.ToString();
if (output.Contains(",") || output.Contains("\""))
output = '"' + output.Replace("\"", "\"\"") + '"';
return output;
}
/// <summary>
/// Output all rows as a CSV returning a string
/// </summary>
public string Export()
{
StringBuilder sb = new StringBuilder();
// The header
foreach (string field in fields)
sb.Append(field).Append(",");
sb.AppendLine();
// The rows
foreach (Dictionary<string, object> row in rows)
{
foreach (string field in fields)
sb.Append(MakeValueCsvFriendly(row[field])).Append(",");
sb.AppendLine();
}
return sb.ToString();
}
/// <summary>
/// Exports to a file
/// </summary>
public void ExportToFile(string path)
{
File.WriteAllText(path, Export());
}
/// <summary>
/// Exports as raw UTF8 bytes
/// </summary>
public byte[] ExportToBytes()
{
return Encoding.UTF8.GetBytes(Export());
}
}
