Modal over modal?

Question

Hi. I'm opening a form like a "popup" as in an alarm clock.

The problem is: I don't know if a modal form is open at this moment, and the popup form needs to be a modal (I think but not sure), so I have a potential (and not so potential) crash.

How can I avoid it?

Thanks.

Answer 1

Lets say we have two forms:

• MainForm - the app form
• AlertForm - to popup timer window.

Add global variables (or static variables):

 

<em>Public Alert as AlertForm</em>

 

When the alarm rings, do this:

 

If Not Alert.Visible Then

Alert.ShowDialog()<br/><br/>Else<br/><br/>''' Alerter arleady showing<br/><br/>End If

 

Answer 2

Thanks. I'll try it later and I'll tell you the results.

Answer 3

Hi. I don't read correctly you post. And surely I don't explain myself.

I don't need to know if the alarm for is open. What I need to do is open the alarm form over another modal form.

Thanks.

Answer 4

Hi DrGerry,

Typically, a modal form cannot be displayed when another modal form is being displayed by the same process. However, we can open a modeless window as a modal window from its parent window with using below three APIs: (be aware modeless window is modal to its parent window only)

• EnableWindow function - http://msdn.microsoft.com/en-us/library/windows/desktop/ms646291(v=vs.85).aspx
• SetForegroundWindow function - http://msdn.microsoft.com/en-us/library/windows/desktop/ms633539(v=vs.85).aspx
• GetWindowLong function - http://msdn.microsoft.com/en-us/library/windows/desktop/ms633584(v=vs.85).aspx

For instance, you have Main form opened with .ShowDialog, with using these three APIs, you can open the alarm form as a modeless window.

Please check this sample code for details. It is writen for WPF, but is adapt for Winform as well. http://code.msdn.microsoft.com/Modeless-Window-in-WPF-492cb24f

Have a nice day,

---

Kee Poppy [MSFT]
MSDN Community Support | Feedback to us

Answer 5

Thanks.