Program.cs

using System.Text;

namespace PasswordGenerator
{
    public static class RandomString
    {
        private static void Main(string[] args)
        {
            Console.Title = "Lilyy2565 Password Generator";
            if (args.Length == 0)
            {
                bool lenError = false;
                int len = 15;
                while (true)
                {
                    Console.Clear();
                    Console.BackgroundColor = ConsoleColor.DarkMagenta;
                    Console.ForegroundColor = ConsoleColor.White;
                    Console.WriteLine(" * Lilyy2565 Password Generator * ");
                    Console.ResetColor();
                    Console.WriteLine("Press [LARROW] or [RARROW] increase or decrease the amount of characters in the password.");
                    Console.WriteLine($"Current length: {len}\n");
                    if (lenError)
                    {
                        Console.BackgroundColor = ConsoleColor.Red;
                        Console.ForegroundColor = ConsoleColor.White;
                        Console.WriteLine(" ! Password cannot be of length less than 1.\n");
                        Console.ResetColor();
                    }
                    Console.WriteLine("Generated Password: " + Generate(len));
                    lenError = false;
                    var key = Console.ReadKey();
                    if (key.Key == ConsoleKey.RightArrow)
                    {
                        len++;
                    }
                    else if (key.Key == ConsoleKey.LeftArrow)
                    {
                        if (len == 1)
                        {
                            lenError = true;
                        }
                        else
                        {
                            len--;
                        }
                    }
                }
            }
            else
            {
                Console.WriteLine(Generate(Convert.ToInt32(args[0])));
            }
        }


        private static Random random = new Random();
        public static string Generate(int length)
        {
            const string chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789!\"£$%^&*(){}[];:'@#~,<.>/?\\|-_=+`¬¦";
            StringBuilder result = new StringBuilder(length);
            for (int i = 0; i < length; i++)
            {
                result.Append(chars[random.Next(chars.Length)]);
            }
            return result.ToString();
        }
    }
}