private void button1_Click(object sender, EventArgs e)
        {
            Frm f = new Frm();
            f.StartPosition = FormStartPosition.Manual;//窗体的位置由 System.Windows.Forms.Control.Location 属性确定
            f.Location = new Point(200,200); //开启时的左上角坐标
            f.ShowDialog();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            this.Location = new Point(300, 410); //移动当前窗口到指定位置
        }