I am attempting to use tib_cursor to populate the Items and
ItemValues of a TIB_ComboBox. Using some sample code from one of the
Tech Info Sheets I tried the following in the FormCreate event:

HMSDataModule.ReadOnlyTransaction.StartTransaction;
cBox.Items.Clear;
cBox.ItemValues.Clear;
with myCursor do
begin
First;
while not Eof do
begin
cBox.Items.Add(myCursor.FieldByName('myCode').AsString);
cBox.ItemValues.Add(myCursor.FieldByName('myKey').AsString);
Next;
end;
Close;
end;
HMSDataModule.ReadOnlyTransaction.Commit;

The cursor was configured with both AutoFetchAll and AutoFetchFirst
set to true, and retrieves 19 records.

Oddly enough, this would NOT work as expected and the ComboBox would
always ended up empty. Debugging the code I discovered that Eof was
true on the first pass of the loop.

Through some experimentation, I found that I COULD make this work by
using the TIB_Cursor AfterFetchRow event to perform the 2 cBox Add
lines. So my FormCreate event now looked like the following:

HMSDataModule.ReadOnlyTransaction.StartTransaction;
cBox.Items.Clear;
cBox.ItemValues.Clear;
with myCursor do
begin
First;
while not Eof do
begin
Next;
end;
Close;
end;
HMSDataModule.ReadOnlyTransaction.Commit;

Through more experimentation if found that the loop was unneccessary
and the final code below would achieve the desired results.

HMSDataModule.ReadOnlyTransaction.StartTransaction;
cBox.Items.Clear;
cBox.ItemValues.Clear;
myCursor.First;
myCursor.Close;
HMSDataModule.ReadOnlyTransaction.Commit;

Could someone please explain this confusing behavior to me, most
importantly:

1. Why did the first snippet not work? It is nearly identical to
sample code in the "Datasets Tech Info Sheet".

2. Why does the final form work even though I am no longer looping
through the cursor? Is the "AutoFetchAll" causing this. Would it
still work without the loop if I were to retrieve, say, 1000
records? If the loop is not needed, what is the advantage to
including it?

Thanks.

Bob