void formLabelConfig_FormClosed(object sender, FormClosedEventArgs e) { formLabelConfig = null; }
private void btnLabelConfig_Click(object sender, EventArgs e) { if (formLabelConfig == null) { formLabelConfig = new FormLabelConfig(); formLabelConfig.FormClosed += formLabelConfig_FormClosed; formLabelConfig.MdiParent = this; } formLabelConfig.WindowState = FormWindowState.Maximized; formLabelConfig.Show(); formLabelConfig.BringToFront(); }