Hi Dave ----

That does blow. If you're into VFP6, you can avoid that whole SET CLASSLIB stuff with NEWOBJECT()....otherwise, I guess you could maintain an array of the objects instanced from the released classlib and release them 1 by one via ASACN().


>I hope I'm wrong but I think I've found a glitch in the way VFp appears to clear a class definition from memory. If no instances of a class exist and SET CLASSLIB TO is issued then all the class definitions should also be released. However this doesn't appear to be true...
>
>Here's an app that demonstrates the problem (you'll need to build a project t1 as described below before running this)...
>

>* Here's the code from t1.app's main program...
>*	set classlib to tshell
>*	local x
>*	x= CreateObject('MyClass')
>*	* this class should be created visually and added to t1
>*         project - simply a generic "custom" class
>
>* === Test Program Start ===
>cs= 't1'
>build app (m.cS) from (m.cS)
>
>do (m.cs + '.app')
>set classlib to
>
>ok= .T.
>on error ok = .F.
>x= CreateObject('MyClass')
>if ! m.ok
>	* this is what we expect of course
>	MessageBox('Cannot create a "MyClass" object', 64, 'TShell')
>	* so it looks as if the class library has been properly cleared
>endif
>
>ok= .T.
>erase t1.app
>* will fail
>messagebox('Erase before clear class: ' + iif(m.ok, 'Succeeded', 'Failed'), 64, 'TShell')
>
>* This shouldn't be necessary, but is!
>clear class myclass
>ok= .T.
>* will succeed
>erase t1.app
>messagebox('Erase after clear class: ' + iif(m.ok, 'Succeeded', 'Failed'), 64, 'TShell')
>
>on error
>
>

>
>The problem this creates is that I can't easily run a 'shell' program which self installs new versions of a program because any module which does get released properly remains bound up in memory. So even though I can actually fire up the new app the old app remains 'somewhere in the ether'. I would imagine that this issue would have implications for things like COM objects as well but I've yet to play with those.
>I can work around this by explicitly clearing every single class. But I know of no command/function that will list the classes that have been instantiated at some point.