Callback Function

[moonoo]

What is a CALLBACK function ? Why it is used ?<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Thanks<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Moonoo

 

[gleason]

A callback function is a function that you write that could be called by outside code (i.e. by windows functions).&nbsp;&nbsp;You set up a callback function by passing the address of your function to the API from which your callback is referenced.<br><br>For example, I want my application to handle runtime exceptions rather than letting C++ runtime take care of things for me.&nbsp;&nbsp;So I wrote a function called my_exception_handler(int, EXCEPTION_POINTERS*) and I call a Microsoft function called _set_se_translator and pass it the address of my_exception_handler.&nbsp;&nbsp;<br><br>In the example above, my_exception_handler is a callback function -- I will never call it myself, but I pass the address of it to an API that will cause it to possibly be called.<br><br>Hope that helps!<br><br> <p>Pat Gleason<br><a href=mailto:gleason@megsinet.net>gleason@megsinet.net</a><br><a href= > </a><br>

 

[Karl Blessing]

its basically a Function pointer, it points to a function in memory, can be used inside and outside of a programming language some languagues cannot use callback functions from say VC++, like visual basic cant(unless you use an API by another dll and such) <p>Karl<br><a href=mailto:kb244@kb244.8m.com>kb244@kb244.8m.com</a><br><a href=

http://kb244.8m.com>

</a><br>Experienced in , or have messed with : VC++, Borland C++ Builder, VJ++6(starting),VB-Dos, VB1 thru VB6, Delphi 3 pro, Borland C++ 3(DOS), Borland C++ 4.5, HTML,Visual InterDev 6, ASP(WebProgramming), QBasic(least i didnt start with COBOL)