关闭外部已经开启的程序

        private void add()
        {
            listBox1.Items.Clear();
            foreach (Process p in Process.GetProcesses())
            {
                if(p.MainWindowTitle!="")
                listBox1.Items.Add(p.MainWindowTitle);
            }
        }
        private void button1_Click(object sender, EventArgs e)
        {
            if (listBox1.SelectedItems.Count > 0) 
            {
                //根据指定的进程名创建进程资源数组
                Process[] prs = Process.GetProcessesByName(listBox1.SelectedItem.ToString());
                foreach (Process p in prs)                      //遍历数组
                    p.CloseMainWindow();                        //关闭拥有进程的界面
                add();                                          //调用刷新
            }
        }