public static FormToolBox GetInstance() { //存储唯一对象的字段为空,或者窗口对象已经被释放 if (ftb == null || ftb.IsDisposed) { ftb = new FormToolBox(); ftb.MdiParent = FormParent.ActiveForm; } return(ftb); }
private void toolBoxToolStripMenuItem_Click(object sender, EventArgs e) { FormToolBox.GetInstance().Show(); }