How to parse CSV files in C#

There's various ways to parse CSV files. Some don't always work well and some do work well but are bigger than you might want.

This is a simple C# class that can read a CSV file line by line and provide the row's column values in a List<string>.

It can handle values with or without delimiters (quotation marks), and carriage returns/line feeds within delimited values.

Usage example:

CsvReader file = new CsvReader(Server.MapPath("file.csv"));

while (!file.EndOfFile)
{
	List<string> row = file.Read();

	if (row != null)
	{
		//do something with each cell, eg. row[0]
	}
}

file.Close();

The class:

public class CsvReader
{
	private StreamReader _reader;

	private bool _endOfFile;

	public bool EndOfFile
	{
		get
		{
			return this._endOfFile;
		}
	}

	public CsvReader(string file)
	{
		this._endOfFile = false;
		this._reader = new StreamReader(file);
	}

	public List<string> Read()
	{
		if (this._endOfFile)
		{
			return null;
		}

		string line = this._reader.ReadLine();

		if (line == null)
		{
			this._endOfFile = true;

			return null;
		}

		List<string> result = new List<string>();

		bool inDelimiters = false;

		int startPos = 0;

		int pos = 0;

		while (pos <= line.Length)
		{
			string chr = (pos < line.Length ? line.Substring(pos, 1) : null);

			if (chr == """ && !inDelimiters && pos == startPos)
			{
				inDelimiters = true;
			}
			else if (chr == """ && inDelimiters)
			{
				if (pos == line.Length - 1)
				{
					result.Add(line.Substring(startPos + 1, pos - (startPos + 1)).Replace("""", """));

					break;
				}
				else if (line.Substring(pos + 1, 1) == ",")
				{
					result.Add(line.Substring(startPos + 1, pos - (startPos + 1)).Replace("""", """));

					pos++;

					startPos = pos + 1;

					inDelimiters = false;
				}
				else if (line.Substring(pos + 1, 1) == """)
				{
					pos++;

					if (pos == (line.Length - 1))
					{
						string nextLine = this._reader.ReadLine();

						if (nextLine == null)
						{
							throw new Exception("CSV file is invalid");
						}

						line += "\n" + nextLine;
					}
				}
			}
			else if (chr == "," && !inDelimiters)
			{
				result.Add(line.Substring(startPos, pos - startPos));

				startPos = pos + 1;

				if (startPos == line.Length)
				{
					result.Add(string.Empty);
				}
			}
			else if (pos == (line.Length - 1) && inDelimiters)
			{
				string nextLine = this._reader.ReadLine();

				if (nextLine == null)
				{
					throw new Exception("CSV file is invalid");
				}

				line += "\n" + nextLine;
			}
			else if (pos == line.Length - 1)
			{
				result.Add(line.Substring(startPos, (pos + 1) - startPos));

				break;
			}

			pos++;
		}

		return result;
	}

	public void Close()
	{
		if (this._reader != null)
		{
			this._reader.Close();
			this._reader = null;
		}
	}

	~CsvReader()
	{
		this.Close();
	}
}