If you don't mind my asking, did you get around it? If so, how? I tried
not unlocking the record, and that would give me chunk underlocked errors if
the record was selected multiple times. Thanks for the suggestions,
Andrew
<[EMAIL PROTECTED]> wrote in message news:22290@palm-dev-forum...
>
> I had the NULL handle problem with redrawing my table cells before. I'm
> using my own custom table drawing callback to draw my cells.
> The way I get data for the cell is to use recH=DmGetRecord(xxx, index),
> and after I'm done drawing, I did a MemHandleFree(recH).
> Which is wrong and BAD. Because the next time I try to access that same
> record index, there is no MemHandle to it, and I'm trying to draw data
> from it.
> MemHandles can be multiple locked, and the only way for a
> DmQueryRecord() to return a NULL handle is if DmQueryRecord() doesn't
> have anything to return (like a record that has already been freed?). So
> says the documentation.
>
> Hope this helps, chances are, I haven't given you all possible
> explanations. I've only been doing this for a couple of months.
>
>
> Andrew Lathrop wrote:
> >
> > I have a table in my app. The way i am using the table, once the user
> > selects a table item, they then have to click a button to edit the
record,
> > delete it, etc. The table and buttons work fine. But, if the user
double
> > clicks the table selection, (selects it twice without clicking anything
> > else) two things happen. 1) For any record besides the first, the cell
is
> > redrawn with some new value. 2) I get an error about MemoryMgr.c
causing a
> > NULL handle error.
> > The only reason i can come up with for the NULL handle error is that the
> > handle is locked, and then locked again without being unlocked.
> > I have the following two lines of code where the error appears to come
from.
> > I have a breakpoint set at precord =, and can see that hrecord has a
value,
> > except when it is double clicked. Then the value is 0x00000000, which
> > causes the error since it then tries to lock the memory at that
location,
> > and none exists. Is there anyway around this?
> > hrecord = DmQueryRecord( sonomaDB, record );
> > precord = MemHandleLock( hrecord );
> >
> > Thanks,
> > Andrew
>
>
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