Brad's suggestion will get you working, but when you have just one
variable string, you can make future packing easy by putting this field
at the end in your definition of the struct type. The code below is from
one of my projects where I know the size of the first two arrays are
always 6 & 4, but the last may be 3 chars or 50...
MemHandle ThisCatchRecHandle;
typedef struct
{
Char Lbs[6];
Char ID[4];
Char Species[1]; // defining it this way keeps the compiler off
your back when the last item is of varying length
}CatchRecord;
CatchRecord * ThisCatchRec, * LockedCatchRecord;
switch (ThisEType)
{
case winEnterEvent:
frmP = FrmGetActiveForm();
FrmSetFocus (frmP,FrmGetObjectIndex
(frmP,fldEnterLbs));
break;
case ctlSelectEvent:
if (eventP->data.ctlSelect.controlID == LbsOK)
// tapped the OK button
{
UInt32 StrLen,CatchRecLen;
UInt16 atPos = 0;
MemHandle RecHandle;
// get numeric string from field
strLbs =
FldGetTextPtr(GetObjectPtr(fldEnterLbs));
StrXLen = StrLen(gSelectedStr); // don't
know how long this one is
CatchRecLen = StrXLen + 10; // 10 is the
sum of .Lbs and .ID's memory
ThisCatchRecHandle =
MemHandleNew(CatchRecLen);
ThisCatchRec =
MemHandleLock(ThisCatchRecHandle);
// create byte record
RecHandle = DmNewRecord(gCatchDBRef,
&atPos, CatchRecLen);
LockedCatchRecord =
MemHandleLock(RecHandle);
StrCopy(ThisCatchRec->Lbs,strLbs);
StrCopy(ThisCatchRec->ID,gSelectedID);
StrCopy(ThisCatchRec->Species,gSelectedStr);
/*
Parameters <-> recordP Pointer to locked data record (chunk pointer).
-> offset Offset within record to start writing.
-> srcP Pointer to data to copy into record.
-> bytes Number of bytes to write.*/
// write to gCatchDBRef
err = DmWrite (ThisCatchRec,
0,LockedCatchRecord, CatchRecLen);
err = DmReleaseRecord (gCatchDBRef
,atPos,true);
MemHandleUnlock(RecHandle);
MemHandleUnlock(ThisCatchRecHandle);
MemHandleFree(ThisCatchRecHandle);
gSelected = false;
}
break;
> -----Original Message-----
> From: [EMAIL PROTECTED]
[mailto:bounce-palm-
> [EMAIL PROTECTED] On Behalf Of Yogesh Saletore
> Sent: Friday, August 22, 2003 5:09 PM
> To: Palm Developer Forum
> Subject: Strings and databases
>
> Hello,
> I'm fairly new at C for Palm and Palm programming. I need some help
with
> recording strings in databases. Right now I just want it to work,
and
> don't
> really want to deal with any packing until later.
>
> I have an error message I want to store, and it is part of a larger
> struct:
> typedef struct
> {
> char *note;
> enum ErrorLevel level;
> Boolean read;
> } ErrNote;
>
> As you can see, note is a string pointer. Now I have all of my error
> messages as string literals: "lasdkf". I copy them one by one,
depending
> upon which are needed, into a tempory string array: noteText[300].
My
> problem is getting the data from noteText into ErrNote note.note. In
> order
> to use StrCopy, I must reference the *note pointer to some memory
block.
> The
> initial copying appears to work fine. I then copy ErrNote note to
the
> database using DmWrite, and then the string as well, using
DmStrCopy.
> The
> error results when I attempt to read back that same string from the
> database. It seems that it wants to use the same memory block I had
> first
> referenced it to, which now no longer exists. Therefore, I receive
many
> memory errors of it attempting to access memory incorrectly. If I
leave
> the
> memory block as is, locked and don't free it, it works fine, but I
then
> have
> a memory leak.
>
> Can anyone please help me find a way to copy the contents of
noteText
> into
> ErrNote note.note?
>
> Thanks,
> Yogesh Saletore
>
>
>
> --
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