winform里怎么通过线程开启新窗体

        private void Nullfun()

        {

            Thread.Sleep(5000);

        }



        

        private void timer1_Tick(object sender, EventArgs e)

        {

            Nullfun();

            Form2 f = new Form2();

            f.Show();

        }

这里的timer用的是System.Windows.Forms.Timer下的.用这个timer子窗体不会卡死,但是界面会.
但是如果换成System.Timers.Timer,子窗体启动后就会一直卡死.究竟怎么写才好呢
------解决方案--------------------

            new Thread(() =>

            {

                Thread.Sleep(5000);

                Application.Run(new Form2());

            }).Start();