Scott's method works fine.
However, let me try to clear up some basic matters about
FldSetTextHandle vs. FldSetText.
A field deals with its contents without regard to how
it got them. That is to say, if you call FldSetTextHandle, it
will get the size of handle and use that to call FldSetText
with a zero offset.
i.e.
FldSetTextHandle(fld, h);
is equivalent to:
FldSetText(fld, h, 0, MemHandleSize(h));
A field is designed to allow dynamic changing of its
text (indeed, that is its main reason for existing).
It will resize the handle, leaving the area before
the offset alone and shifting the area after the offset + size
as needed as the text grows or shrinks. This can result
in the handle becoming invalid, so you should always
fetch it back from the field when you need it again.
Only one field can be active in a form at a time. You
can have multiple fields all pointing into the same handle.
In this case, you should use the load data and save data
callbacks to insure that everything stays coordinated.
This is a complicated strategy, but it does work
(see the address book example's edit view for an implementation).
The complications involved in this strategy lead many to take
Scott's approach. This burns some extra memory, but it
also works just fine and many consider it to be more
straightforward. You pays your money and you takes your chances...
-bob mckenzie
-----Original Message-----
From: Scott Brooks [mailto:[EMAIL PROTECTED]]
Sent: Monday, July 16, 2001 6:17 AM
To: Palm Developer Forum
Subject: Re: FldSetText Question
I just use another variable and fill it with the text I want.
Here, I grap a value I call "pCount":
UInt16 YOUR_TEXT_LENGTH = 9, YOUR_OFFSET = 4;
recHandle = DmGetRecord(testDB, CurrentItem);
recText = MemHandleLock(recHandle);
pCountHandle = MemHandleNew(YOUR_TEXT_LENGTH);
pCountText = MemHandleLock(pCountHandle);
// first initiallize it with an array of NULL's
MemMove(pCountText, fillerNineLong, YOUR_TEXT_LENGTH);
MemMove(pCountText, recText + YOUR_OFFSET, YOUR_TEXT_LENGTH);
MemHandleUnlock(pCountHandle);
fldIndex = FrmGetObjectIndex(frm, SPECIFIEDField);
FldSetTextHandle(FrmGetObjectPtr(frm, fldIndex), pCountHandle);
MemHandleUnlock(recHandle);
DmReleaseRecord(CycleCountDB, CurrentItem, 0);
Regards,
Scott
>From: "George R" <[EMAIL PROTECTED]>
>Reply-To: "Palm Developer Forum" <[EMAIL PROTECTED]>
>To: "Palm Developer Forum" <[EMAIL PROTECTED]>
>Subject: FldSetText Question
>Date: Mon, 16 Jul 2001 08:34:41 -0400
>
>I'm trying to use FldSetText to set a handle to a field. My handle is
>actually a pointer to a record in my database. I want to set portions of
>the
>handle that correspond to database fields to different form fields. Thus I
>don't want to use FldSetTextHandle. While FldSetText is supposed to allow
>you to set the number of bytes you wish to set, it doesn't appear to be
>working right. Has anyone had any experience using FldSetText to set subset
>of a handle that's NOT a null terminated string (my database does not use
>null terminated strings for each field)? When I try it, I get a debug error
>saying "Text Block Size smaller than Text", and the field is populated with
>more data than I request (eac field hsows data up to the NULL termination,
>regardless of the size I send).
>
>Also, does FldSetText allow you to edit the field or not? I've read
>conflicting statements on this, but the latest Palm OS Reference says
>FldSetText and FldSetTextHandle allow you to edit fields in place.
>
>Below are the relevant sections of my code:
>// totalOffset holds the number of bytes at the ebginning of each record
>used to store field offset sizes.
>
> record = cursor;
> maxColumns = numColumns;
> dataRecord = DmQueryRecord (dataDB, record);
> precord = (Char*) MemHandleLock (dataRecord);
> FrmDrawForm (form);
> details = MemHandleNew (MemHandleSize (dataRecord) - totalOffset);
> stringT = (Char*) MemHandleLock (details);
> StrCopy (stringT, precord + totalOffset);
> MemHandleUnlock (dataRecord);
> MemHandleUnlock (details);
> for (loopIndex = 0; loopIndex < numColumns; loopIndex++)
> {
> if (loopIndex == 0)
> {
> offset = 0;
> fieldSize = 4;
> }
> else if (loopIndex == 1)
> {
> offset = 4;
> fieldSize = 9;
> }
> else
> {
> offset = 12;
> fieldSize = 9;
> }
> fieldIndex = FrmGetObjectIndex (form, fieldID);
> fieldPtr = (FieldType*) FrmGetObjectPtr (form, fieldIndex);
> FldSetText (fieldPtr, details, offset, fieldSize);
> FldSetUsable (fieldPtr, true);
> FldDrawField (fieldPtr);
> fieldID++;
> }
>
>--
>George R
>
>
>
>
>--
>For information on using the Palm Developer Forums, or to unsubscribe,
>please see http://www.palmos.com/dev/tech/support/forums/
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