C#怎么通过指定进程ID结束进程

using System;
using System.Diagnostics;

namespace HelloWorld.utils
{
   class ProcessCmdUtils
   {
		//开启一个进程，执行传入的CMD DOS命令
       public static Process ExecCmd()
       {
           //cmd = cmd.Trim().TrimEnd('&') + "&exit";


           Process p = null;
           try
           {
               p = new Process();
               p.StartInfo.FileName = "cmd.exe";
               p.StartInfo.UseShellExecute = false;        //是否使用操作系统shell启动
               p.StartInfo.RedirectStandardInput = true;   //接受来自调用程序的输入信息
               p.StartInfo.RedirectStandardOutput = true;  //由调用程序获取输出信息
               p.StartInfo.RedirectStandardError = true;   //重定向标准错误输出
               p.StartInfo.CreateNoWindow = true;          //不显示程序窗口
           }
           catch (Exception e)
           {
               throw;
           }

           return p;
       }

		//根据传入的进程ID，强制结束指定进程
       public bool KillProcExec(int procId)
       {
           string cmd = string.Format("taskkill /f /t /im {0}", procId); //强制结束指定进程

           Process ps = null;
           try
           {
               ps = ExecCmd();
               ps.Start();
               ps.StandardInput.WriteLine(cmd + "&exit");
               return true;
           }
           catch
           {
               throw;
           }
           finally
           {
               ps.Close();
           }
           

           return false;
       }
   }
}

 static int psTaskID = -1; //检测是否有上次执行的task，如果值为-1，则执行，否则kill掉上次执行未完成任务
  
  private void button1_Click(object sender, EventArgs e)
       {
           Console.WriteLine("method ininer " + psTaskID);

			//检测psTaskID 是否为-1，如果不是，则执行KillProcExec()方法
           if (psTaskID != -1)
           {
               ProcessCmdUtils procKill = new ProcessCmdUtils();
               bool killStatus=procKill.KillProcExec(psTaskID);
               Console.WriteLine("try external "+psTaskID);
               if (killStatus)
               {
                   psTaskID = -1;
               }
           }

           try
           {

               string address = textBox1.Text;

               string cmd = "TRACERT.exe " + address;

               ps = ProcessCmdUtils.ExecCmd();


               ps.Start();

               psTaskID = ps.Id;//获取运行的process ID 赋值给 paTaskID

               Console.WriteLine("try ininer "+psTaskID);

				//other code 其他代码，暂不演示
           }
           catch
           {
               throw;
           }
           finally
           {
               ps.Close();
           }
       }