How do I get a user control to be closed when I close a specific form?

When I open from the main screen of the application a child form I开发者_高级运维 also display a user control that should be displayed until the child form is closed or the user closes it. If I set the child form to be usercontrol's parent, the user control is not displayed (so the parent of the user control is the desktop). I used SetWindowPos with HWND_TOPMOST and I get the correct behaviour. now when I close the child form I want the usercontrol to close as well. Do you know what I shoud do to get this? thanks,

---

When you Show() the child you can also subscribe to it's Closed or Closing event and use that to properly close the UC.

var f = new ChildForm();
// show userctl

f.Closed += MainForm_ChildClosed_Handler;



void MainForm_ChildClosed_Handler(object s, EventArgs e) 
{
    // close/hide userctl
}

---

If you keep a reference towards your usercontrol, you should be able to Close (or even Dispose) it from the Closingevent of his parent.

---

I don't know what you are doing, a UserControl is meant to be a child control, it should be embedded in a Form. It is technically possible to turn a UC into a top level window (like Form), you'd have to set the TopLevel property to True. That however isn't very productive, the window doesn't have the chrome to make it friendly to use. It is missing the title bar, no easy way for the user to move it around, minimize it, close it. And no easy way to solve focus problems, it can disappear behind another window with no easy way for the user to bring it back to the front. Making it top-most is a hack of sorts to get at least the focusing problem solved, but at rather a deer cost.

Just use the UC as it was intended to be used: put it inside a form. That form should probably be the child form you open. It could also be a third form, say a tool window. Use the Show(owner) overload to keep its Z-order in check and cannot do the disappearing act. That also causes it to automatically close when the owner closes.