TOpenDialog in Delphi - how to open only file with given name

Question

User should open only "KLADR.DBF" file. I'm setting "Filter" property to "kladr.dbf" and dialog shows only required file, but in the same directory there are another ".DBF" file (STREET.DBF) and user can open it by typing it's name in "Filename:" edit box. How can I prevent this and let users select only required "KLADR.DBF" file?.

Here is screen demonstrating this issue:

Answer 1

TOpenDialog has an event OnCloseQuery. Provide an event handler that checks for the validity of the name, and if the app shouldn't accept the name then show a message to the user and set CanClose to False.