C#单例模式

子窗体：

Form_employee_Quit fm; string userId; DataTable sesstab; private Form_employee_Quit_Handle(Form_employee_Quit fmz,string Code) { InitializeComponent(); userId = Code; fm = fmz; } private static Form_employee_Quit_Handle instance; //三.通过静态方法创建字窗体 public static Form_employee_Quit_Handle CreateFrom(Form_employee_Quit fmz, string Code) { //判断是否存在该窗体,或时候该字窗体是否被释放过,如果不存在该窗体,则 new 一个字窗体 if (instance == null || instance.IsDisposed) { instance = new Form_employee_Quit_Handle(fmz,Code); } else { instance.Focus(); } return instance; }

父窗体：

//添加 --单例模式 private void simpleButton2_Click(object sender, EventArgs e) { Form_employee_Quit_Handle frm_Quit = Form_employee_Quit_Handle.CreateFrom(this, fm.lbluserLog.Text.Trim()); frm_Quit.Show(); }