WinForm窗体关闭事件

是的,你可以,这很简单:

private void LoadChildForm_Click(object sender, EventArgs e)
{
    ChildForm form = new ChildForm();
    form.FormClosed += new FormClosedEventHandler(ChildFormClosed);
    form.Show();
}

void ChildFormClosed(object sender, FormClosedEventArgs e)
{
    // do something useful
}