C#マルチスレッドパラメータ

    class test
    {
        private int i ;
        private string s;
        public test(int n1,string s1)
        {
            this.i = n1;
            this.s = s1;
        }
        public void Withparameters()
        { 
         Console.WriteLine(" ， {0},{1}",i,s);
        }
    }
    class Program
    {
        static void Main()
        {
            Thread th = new Thread(new ParameterizedThreadStart(WithParameters));// parameterizedThreadStart object 。 object ， 
            th.Start("ParameterizedthreadStart");
            test t=new test(123," ");// 
            Thread th1 = new Thread(t.Withparameters);
            th1.Start();
            Thread th2 = new Thread(() => WithParameters("lambda"));//lambda 。
            th2.Start();
            Console.ReadKey();
        }
        static void WithParameters(object obj)
        {
            string o = obj as string;
            if (!string.IsNullOrEmpty(o))
            {
                Console.WriteLine(" ， {0}",o);
            }
        }
    }