Hi,
see my comment below.
In article <94483@palm-dev-forum>, "Sean Rogers" <[EMAIL PROTECTED]>
wrote:
> I'm having problems with my database usage. At the moment, I'm just trying
> to save a name entered by the user in a text field and display that saved
> name in a different form. I know databases aren't necessary for trivial
> things like this, but I'm starting out easy to get my head around databases.
> Can anyone help me out?
>
> First, I've got a struct like this:
>
> typedef struct {
> char TrackName[20];
> } DBRecord;
>
>
> Here's my saving code:
>
> FieldPtr fld;
> FormPtr frm;
> Int itemIndex;
> CharPtr newTrackName;
> VoidHand h;
> UInt16 index = 0;
> DBRecordType r;
>
> frm = FrmGetActiveForm();
> itemIndex = FrmGetObjectIndex(frm, TrackRecordNameField);
> fld = FrmGetObjectPtr(frm, itemIndex);
> newTrackName = FldGetTextPtr(fld);
> h = DmNewRecord(DB, &index, sizeof(r));
> StrCopy(r.TrackName, newTrackName);
You should use StrNCopy instead StrCopy. The user should enter a string
longer than 20 chars.
> if (h) {
> VoidPtr p = MemHandleLock(h);
> Err err = DmWrite(p, 0, &r, sizeof(r));
> MemPtrUnlock(p);
> DmReleaseRecord(VictoryDB, index, true);
> }
>
>
> And here's my loading code:
>
> FieldPtr fld;
> FormPtr frm;
> Int itemIndex;
> CharPtr newTrackName = 0;
> VoidHand h;
> UInt index = 0;
>
> frm = FrmGetActiveForm();
> itemIndex = FrmGetObjectIndex(frm, ShowTrackNameField);
> fld = FrmGetObjectPtr(frm, itemIndex);
> // get the handle to the record
> h = DmQueryRecord(VictoryDB, index);
> if (h) {
> DBRecordType * p = (DBRecordType *) MemHandleLock(h);
> StrCopy(newTrackName, p->TrackName);
You have to allocate the pointer before copying something in it.
> MemPtrUnlock(p);
> }
> FldSetTextPtr(fld, newTrackName);
> FldDrawField(fld);
>
If you use the FldSetTextPtr function, don't forgot to set the EditField
as non-editable.
Don't forgot to release the newTrackName pointer after to avoid memory
leaks.
Ludovic
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