Question

I was creating some complex applications in Visual Basic .NET 2008 and since they are in the testing phase right now, people manage to find an error or two every so often that causes the program to crash. The problem is that there is a tracking piece to it that logs who is currently using the programs. When a user logs in, it logs that they are currently logged in, and if the form close event is fired, the log is deleted to show that they have closed it.

Now my problem comes whenever the form crashes from an error since it won’t trigger the close event and therefore makes the log become inaccurate. My question is if it is possible to capture any error that the form would have in the form of an event?

Answer 1

Try double-clicking on “My Project” in the Solution Explorer.

On the “Application” tab, toward the bottom is a “View Application Events” button. Click it.

You should see an “ApplicationEvents” file. Select the UnhandledException event.

It should look like this:

Namespace My

  ' The following events are available for MyApplication:
  ' 
  ' Startup: Raised when the application starts, before the startup form is created.
  ' Shutdown: Raised after all application forms are closed.  This event is not raised if the application terminates abnormally.
  ' UnhandledException: Raised if the application encounters an unhandled exception.
  ' StartupNextInstance: Raised when launching a single-instance application and the application is already active. 
  ' NetworkAvailabilityChanged: Raised when the network connection is connected or disconnected.
  Partial Friend Class MyApplication

    Private Sub MyApplication_UnhandledException(ByVal sender As Object, ByVal e As Microsoft.VisualBasic.ApplicationServices.UnhandledExceptionEventArgs) Handles Me.UnhandledException
      // log your exception here.
    End Sub
  End Class

End Namespace

Note: this event will not fire while a debugger is attached.