c#在命令行窗口得到dos命令信息

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Diagnostics;

namespace ConsoleApplication3
{
    class Program
    {
        static void Main(string[] args)
        {
            ProcessStartInfo psi = new ProcessStartInfo("cmd.exe");
            psi.CreateNoWindow = true;

            psi.RedirectStandardOutput = true;
            psi.UseShellExecute = false;
            psi.Arguments = "/c ping";

            Process p = Process.Start(psi);

            String s = p.StandardOutput.ReadToEnd();

            Console.WriteLine(s);

            Console.ReadLine(); 
        }
    }
}