private void buttonManage_Click(object sender, EventArgs e) { dataGridViewList.Hide(); if (mf == null) { mf = new ManageForm(); mf.MdiParent = this; mf.FormClosed += mf_FormClosed; mf.Show(); } else { mf.Activate(); } }
void mf_FormClosed(object sender, FormClosedEventArgs e) { mf = null; //throw new NotImplementedException(); }