เรียก Method อีก class นึงเพื่อให้ทํา Enable = true ปุ่มกลับมาใช้งานได้ ไม่ได้หรอครับ

Class 1
private void button1_Click(object sender, EventArgs e)
        {
            button1.Enabled = false;
            Form2 frm = new Form2();
            frm.MdiParent = Main.ActiveForm;
            frm.Show();
        }
public void BtnEnabled()
        {
            this.button1.Enabled = true;
        }

Class 2
private void Form2_FormClosed(object sender, FormClosedEventArgs e)
        {
            Form1 frm = new Form1();
            frm.BtnEnabled();
        }

        protected override void OnClosed(EventArgs e)
        {
            foreach (Form cf in this.MdiParent.MdiChildren) {
                if (cf.Name == "Form1") {
                    ((Form1)cf).button1.Enabled = true;
                }
            }
            base.OnClosed(e);
        }

 private void Form2_FormClosed(object sender, FormClosedEventArgs e)
        {
            foreach (Form cf in this.MdiParent.MdiChildren)
            {
                if (cf.Name == "Form1")
                {
                    ((Form1)cf).button1.Enabled = true;
                }
            }
            base.OnClosed(e);
        }