在你的WinForms紧密的形式，它部署它的所有儿童。因此，这不是一个好主意。你需要做的是异步的，例如，你可以发送邮件到父窗体。

When you close form in WinForms it disposes all of it's children. So it's not a good idea. You need to do it asynchronously, for example you can send a message to parent form.