RE: MemPtr Help

[dennis]

iBuffPtr is passed by value:

   iLen = BBB(iBuffPtr);

Therefore, even if BBB changes the value of iBuffPtr, the caller (namely
AAA) will not see the change.

One fix would be to pass a pointer to iBuffPtr.  The above call would look
like:

   iLen = BBB(&iBuffPtr);

and BBB would look like:
//----------------------------------------------------------------------
//----------------------------------------------------------------------
UInt16 BBB(UInt8** iDataPtr)
{
   UInt16 iLen;
   Char sStr[] = "Test Data";
   Err err;

   iLen = StrLen(sStr);
   *iDataPtr = (UInt8*)MemPtrNew(iLen+1);
   err = MemMove (*iDataPtr, sStr,iLen+1);
   return iLen+1;
}
//----------------------------------------------------------------------
//----------------------------------------------------------------------

Hope this helps.

Dennis Leas
-----------
[EMAIL PROTECTED]



-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] Behalf Of Ken
Sent: Tuesday, July 01, 2003 6:13 PM
To: Palm Developer Forum
Subject: MemPtr Help


Hi,

Below is sample code of what I would like to do (which does not work).

Function BBB allocates memory and loads the buffer and then
AAA uses the data and then deletes the buffer.

The pointer to the memory buffer does not get passed back to AAA
correctly.

So I have missed something in the way the MemPtr function work.

I would like to know how to make it work with the MemPtr functions.

Thanks,
Ken

//----------------------------------------------------------------------
//----------------------------------------------------------------------
void AAA(void)
{
   UInt8* iBuffPtr=NULL;
   UInt16 iLen;

   iLen = BBB(iBuffPtr);

   //do something with iBuffPtr

   MemPtrFree(iBuffPtr);
}

//----------------------------------------------------------------------
//----------------------------------------------------------------------
UInt16 BBB(UInt8* iDataPtr)
{
   UInt16 iLen;
   Char sStr[] = "Test Data";
   Err err;

   iLen = StrLen(sStr);
   iDataPtr = (UInt8*)MemPtrNew(iLen+1);
   err = MemMove (iDataPtr, sStr,iLen+1);
   return iLen+1;
}

//----------------------------------------------------------------------
//----------------------------------------------------------------------

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