Generate random string [duplicate]

Answer 1

I know this might not be the best solution, but I kind of like the idea to be able to specify "allowed" characters:

    private const int _defaultNumberOfCharacters = 8;
    private const int _defaultExpireDays = 10;
    private static readonly string _allowedCharacters = "bcdfghjklmnpqrstvxz0123456789";

    public static string GenerateKey(int numberOfCharacters)
    {
        const int from = 0;
        int to = _allowedCharacters.Length;
        Random r = new Random();

        StringBuilder qs = new StringBuilder();
        for (int i = 0; i < numberOfCharacters; i++)
        {
            qs.Append(_allowedCharacters.Substring(r.Next(from, to), 1));
        }
        return qs.ToString();
    }