CVICALLBACK function

[JasonJ 56]

In CVI 7.1, I placed a button in my panel, and generated a callback function from there. In the callback function, the last line is "return 0;", and if I left-clicked the button, I got at least two events: EVENT_COMMIT and EVENT_LEFT_CLICK. Ok, everything is fine, until...
I changed the last line to "return (1);". Then if I left-clicked the button, I only got EVENT_LEFT_CLICK, not EVENT_COMMIT any more.
WHY???????

Jason

[Al_S]

Returning 1 from a callback swallows the event. When the event is swallowed, mouse clicks and keypresses are ignored. There are any number of reasons to intentionally swallow the event, but for normal processing, your callbacks must always return 0.
See the online help for Swallow.