C# Application_Idle does not fire when MessageBox or FileDialogue is active... Any alternates?

We have implemented Application_Idle event in our application. This works great, and users are pr开发者_JS百科omptly asked to enter the password if the session is idle for about 20 minutes.

However, if there is a message-box open or a File Dialogue open to Save/Open the file. Application_Idle never fires. Even if we leave the application idle overnight.

This is a big of a security concern. Any ideas will be appreciated.

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Instead of the idle event use a timer that will lock the application after a configurable timeout. Needless to say, the timer needs to be reset, when the user is interacting with the application.