Here's an actual working DmCompare function from one of our apps:
/***************************************************************************
* FUNCTION: IndexRecordCompare
***************************************************************************/
Int16 Import_RecordCompare (void *rec1, void *rec2, Int16 other,
SortRecordInfoPtr rec1SortInfo, SortRecordInfoPtr rec2SortInfo, MemHandle
appInfoH)
{
Int16 result = 0;
ImportRecPtr recP1;
ImportRecPtr recP2;
Char *t1;
Char *t2;
recP1 = (ImportRecPtr)rec1;
recP2 = (ImportRecPtr)rec2;
t1 = (Char *)&recP1->name;
t2 = (Char *)&recP2->name;
if(other == 0)
result = StrCompare(t1, t2);
else
result = StrCompare(t2, t1);
return(result);
}
ImportRecPtr is delcared similar to:
typedef struct{
Int16 dbVer; // Version number of DB so we can adjust
Int16 someNumber;
Char string[32];
}ImportRecType;
typedef ImportRecType * ImportRecPtr;
They syntax here is broken out for legibility, and we cast the rec1 and rec2
(again for legibility) it can be done other ways like just casting the
compare
StrCompare((ImportRecPtr)rec1->name, ImportRecPtr)rec2->name);
--
Matt Disher
[EMAIL PROTECTED]
> From: Jay Francis <[EMAIL PROTECTED]>
> Reply-To: "Palm Developer Forum" <[EMAIL PROTECTED]>
> Date: Tue, 14 May 2002 13:31:27 -0500
> To: "Palm Developer Forum" <[EMAIL PROTECTED]>
> Subject: DmComparF
>
> Thanks Matt and Hal,
>
> It's a little clearer. It looked like Matt's example
> used a different prototype which was confusing at
> first. Hal's used the pointer to void which is what
> the CmCompareF prototype is looking for. I will test
> these further to see if it's just another way to do the
> same thing.
>
> I'm still not exactly sure what the sortinfo they want
> for each record with the
> SortRecordInfoPtr datatype within the DmComparF
> function.
>
> It's too bad there couldn't be a small sample in the
> API reference manual. Oops sorry that would make
> things clearer.
> Jay
>
>
>
> --
> For information on using the Palm Developer Forums, or to unsubscribe, please
> see http://www.palmos.com/dev/support/forums/
>
--
For information on using the Palm Developer Forums, or to unsubscribe, please see
http://www.palmos.com/dev/support/forums/
