using System;

using System.Linq;

using System.Collections.Generic;

​

var witnesses = new List<Witness> 

{

    new Witness(null, true, 13),

    new Witness(null, false, 6),

    new Witness(null, false, 2)

};

​

var sorted = witnesses

    .OrderByDescending(x => x.m_hasLOS)

    .ThenBy(x => x.m_distanceToSqrt)

    .ToList();

​

foreach (Witness item in sorted)

{

    Console.WriteLine($"{item.m_hasLOS}, {item.m_distanceToSqrt}");

}

​

​

public class Witness

{

    public object m_mobile;

    public bool m_hasLOS;

    public double m_distanceToSqrt;

    public Witness(object m, bool hasLOS, double distanceToSqrt)

    {

        m_mobile = m;

        m_hasLOS = hasLOS;

        m_distanceToSqrt = distanceToSqrt;

    }

}