private void mDI1ToolStripMenuItem_Click(object sender, EventArgs e) { //if (mdi1 == null) //{ mdi1 = new MDI1(); mdi1.MdiParent = this; mdi1.FormClosed += new FormClosedEventHandler(mdi1_FormClosed); mdi1.Show(); //} //else mdi1.Activate(); }
private void mdi1_FormClosed(object sender, FormClosedEventArgs e) { mdi1 = null; }