Question

We developed an application that uses Excel interop libraries (Microsoft.Office.Interop.Excel) to read some Excel files.

When a problem occur in the application, the event Application.ThreadException is handled, so the resources are released (Excel is closed…).

The problem is that when we use the VS debugger, if we stop the execution (because the process breaks on an exception, or a breakpoint, there are lots of reasons why we’d do that), the resources are not released and Excel stays opened.
And of course, next time the application is launched… it crashes because there are locks on the file.

So I’m looking for a way to force the release of the Excel objects, even when stopped with the debugger.

Any suggestion ?

Answer 1

You can use the DTE (VisualStudio Automation Model) to write a macro that will be invoked when a stop debug happens, below is a snippet of the idea.

Private Sub DebuggerEvents_OnEnterBreakMode(
   ByVal Reason As EnvDTE.dbgEventReason, 
   ByRef ExecutionAction As EnvDTE.dbgExecutionAction) Handles DebuggerEvents.OnEnterBreakMode
    If (Reason = dbgEventReason.dbgEventReasonStopDebugging) Then
        // DO YOUR CLEAN UP CODE HERE
    End If
End Sub