Hi Matt,
It looks like the problem is in IntToStr(). The function allocates 7
bytes for ptext off the stack and returns a pointer to them, but once
the function exits the stack is unwound and the pointer becomes invalid.
You'll need to either allocate some memory of the heap using MemPtrNew()
and return that or have the caller pass in a pointer to a buffer as a
parameter.
--
Tony
"Nesselhauf, John" wrote:
>
> I believe you must think in terms of where is the variable pointing to when
> the 2nd function SetTextToField is placed on the stack. It is obviously not
> pointing at the same location. I am no expert in this but if you approach it
> from that aspect it may help you determine a correct course of action. Make
> sure that what is being passed back from IntToStr is a CharPtr. Also, you
> may want to try Locking and Unlocking memory on the variable that is being
> passed.
>
> Hope this helps.
>
> John N.
>
> -----Original Message-----
> From: Matt Becker [mailto:[EMAIL PROTECTED]]
> Sent: Friday, November 10, 2000 10:09 AM
> To: Palm Developer Forum
> Subject: An issue of scope???
>
> Another question for everyone. The following line calls the
> SetTextToField function, described below. Inside this call, it also
> calls IntToStr, as you can see. Now, these 2 functions are in a
> different file than the call.
> 1st. The call to IntToStr is passed a number, and it sucessfully passes
> the resultant string back to file1 and sets pnumstr to the string passed
> back. Now, when SetTextToField is called, the value passed into it is
> random! Why would pnumstr get miss-passed? Its like its not passing
> the value into SetTextToField whatsoever. The value of pnumstr is,
> according to the debugger, correct. But, when the programs shifts to
> the SetTextToField function, the value of ptext that is passed in is
> garbage. Is this an issue of scope? If so, then why doesnt
> MyNum.Number sucessfully get passed into, and back out of IntToStr,
> which is in the same file as SetTextToField. Please help. thanks!
>
> file1.c
> CharPtr pnumstr;
> pnumstr = IntToStr(MyNum.Number);
> SetTextToField(ReviewNumField, pnumstr );
>
> file2.c
> void SetTextToField( Word fieldID, CharPtr ptext )
> {
> FormPtr pform;
> FieldPtr pfield;
> VoidHand hfield;
> CharPtr pfieldtext;
>
> pform = FrmGetActiveForm();
> pfield = FrmGetObjectPtr(pform, FrmGetObjectIndex(pform, fieldID));
> hfield = FldGetTextHandle(pfield);
> if(hfield != NULL)
> {
> MemHandleResize(hfield, StrLen(ptext)+1);
> }
> else
> hfield = MemHandleNew(StrLen(ptext)+1);
> pfieldtext = MemHandleLock(hfield);
> StrCopy(pfieldtext, ptext);
> MemHandleUnlock(hfield);
> FldSetTextHandle(pfield, hfield);
> FldDrawField(pfield);
>
> return;
> }
>
> CharPtr IntToStr(Word num)
> {
>
> Char ptext[7];
> CharPtr ptemp;
>
> ptext[0]='\0';
> ptemp = StrIToA(ptext, num);
>
> return(ptemp);
> }
>
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