public static calculator GetInstance() { if (Instance == null) { Instance = new calculator(); } return(Instance); }
private void 添加ToolStripMenuItem_Click(object sender, EventArgs e) { calculator newWindow = new calculator(); newWindow.Show(this.dockPanel1, AppConfig.ms_floatform); }
private void ShowFloatform() { calculator frmFun = calculator.GetInstance(); frmFun.Show(this.dockPanel1, AppConfig.ms_floatform); }
private void floatform_FormClosed(object sender, FormClosedEventArgs e) { Instance = null; // 否则下次打开时报错,提示“无法访问已释放对象” }