public static FactoryExit CreateForm() { if (_danli == null) { _danli = new FactoryExit(); } return(_danli); }
private void FactoryExit_FormClosing(object sender, FormClosingEventArgs e) { _danli = null; }
private void button7_Click(object sender, EventArgs e) { FactoryExit from = FactoryExit.CreateForm(); from.Show(); }