C# 调用执行CMD命令

using System.Diagnostics;

static  Process  p;
        /// <summary>
        /// 运行CMD命令
        /// </summary>
        /// <param name="cmd">命令</param>
        /// <returns></returns>
        public static string Cmd(string[] cmd)
        {
            
            if (p ==null )
            {
                 p = new Process();
            }
            p.StartInfo.FileName = "cmd.exe";
            p.StartInfo.UseShellExecute = false;
            p.StartInfo.RedirectStandardInput = true;
            p.StartInfo.RedirectStandardOutput = true;
            p.StartInfo.RedirectStandardError = true;
            p.StartInfo.CreateNoWindow = true;
            p.Start();
            p.StandardInput.AutoFlush = true;
            for (int i = 0; i < cmd.Length; i++)
            {
                p.StandardInput.WriteLine(cmd[i].ToString());
            }
            p.StandardInput.WriteLine("exit");
            string strRst = p.StandardOutput.ReadToEnd();
            p.WaitForExit();
            p.Close();
            return strRst;
        }