using System;

using System.Text;

using System.Security.Cryptography;

​

public class Program

{

    public void Main()

    {

        int l = 10;

        string str = GenerateRandomString(l);

        Console.WriteLine(str);

    }

    public string GenerateRandomString(int length)

    {

        if (length < 1)

        {

            return string.Empty;

        }

        string response;

        var codeData = new byte[length];

        using (var randomStringGenerator = new RNGCryptoServiceProvider())

        {

            randomStringGenerator.GetBytes(codeData);

            Console.WriteLine(codeData.ToString());

            response = Encoding.Default.GetString(codeData);

        }

        return response;

    }

​

}