recordchanged

Q: "How can I determine when the current record in a dataset has changed?"

A: Check the DataSource's State property in the OnDataChanged event. The State
    property will be set to dsBrowse if the record position has changed. The
    following example will display a message box every time the record position
    has changed in MyDataSource:

procedure TMyForm.MyDataSourceDataChange(Sender: TObject; Field: TField);
begin
if (Sender as TDataSource).State = dsBrowse then
ShowMessage('Record Position Changed');
end;