TDBLookupListBox.DataChange procedure
Performs actions needed when a new DataField value is selected using the lookup dataset.
Declaration
procedure DataChange(Sender: TObject); overrideDescription
DataChange is an overridden method in
TDBLookupListBox.
It implements the abstract virtual method defined in the ancestor class, and
provides support for setting the value in
ItemIndex when the value
for
KeyField in the lookup dataset has changed.
DataChange uses the internal TFieldDataLink instance in the
control to determine if the linked dataset has been opened. If the dataset is
active, the value in ItemIndex is set to the key index position
from the lookup dataset. If the linked dataset is not active, the value in
ItemIndex is set to -1 (indicating no item is selected in the control).
DataChange is used as the OnDataChange event handler for the
internal TFieldDataLink instance in the control, and called from
the DoSelectionChange method.
See also
An experiment, built from development snapshots. Not the official Free Pascal or Lazarus documentation.