"Craig Graham" <[EMAIL PROTECTED]> wrote: >I'm playing with a library (on Linux) where a particular function call >requires information that it obtains from a callback function. It doesn't >return until the callback has executed, and fails if the callback pointer is >null. > >Old Labviews didn't do callbacks. Can this now be done in 7.1? I'd rather >not go down the route of changing the library and maintaining a local hacked >version.
No it isn't there and in fact would be troublesome to do. No doubt it could be done but the knowledge you would need to be able to configure such a function properly so it doesn't crash is already so high that anyone with that knowledge could easily come up with a wrapper DLL Since you seem to have the DLL source available what I would do is one of two things. Either write a wrapper DLL translating the callback into an occurrence or adding a new LabVIEW nice function which takes an occurrence as parameter and translates the underlying callback into an occurrence event. The first has the advantage of not changing the actual DLL, the second would be interesting if you have a chance of getting the source code modifications back into the main source code tree, so that you don't need to maintain your local copy. As such it is only suited if you have direct involvement in development or a distributed development infrastructure as often used for Open Source projects. I'll be gone for a while with no internet access, but if it is not to urgent I would be willing to show you how such a translation from callback to occurrence could be done, after my return. Rolf Kalbermatter CIT Engineering Nederland BV tel: +31 (070) 415 9190 Treubstraat 7H fax: +31 (070) 415 9191 2288 EG Rijswijk http://www.citengineering.com Netherlands mailto:[EMAIL PROTECTED]
