C#调用命令行时(cmd.exe)，如何让命令行打开的目录为执行程序的目录？

 string command = "dir";

        Process 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 = false;

       // string strOutput = null;

        try

        {

            p.Start();

            Console.WriteLine("command:" + command);

            p.StandardInput.WriteLine(command + "&exit");

            string output = p.StandardOutput.ReadToEnd();

            p.WaitForExit();

            p.Close();

            Console.WriteLine("result:" + output);



        }

        catch (Exception e1)

        {

            Console.WriteLine("error" + e1.Message);

        }