Mega Code Archive
Auto completion for TCombobox
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Title: Auto completion for TCombobox
Question: A smart and handy solution for the auto-complete feature in a TCombobox - works quite well with just a few lines of code.
Answer:
{ A smart and handy solution, easy to understand and,
easy to adapt for your personal requirements.
Don't forget to set the 'Sorted' property of the TCombobox
to true to avoid problems. }
// Add this to the var section of your form:
var
lastKey: Word;
// put the following lines in the OnChange event of the TCombobox
procedure TForm1.AutoCompleteChange(Sender: TObject);
var
SearchStr: string;
retVal: integer;
begin
// copy search pattern
SearchStr := (Sender as TCombobox).Text;
// backspace: VK_BACK or $08
if lastKey VK_BACK then
begin
retVal := (Sender as TCombobox).Perform(CB_FINDSTRING, -1, LongInt(PChar(SearchStr)));
if retVal CB_Err then
begin
(Sender as TCombobox).ItemIndex := retVal;
(Sender as TCombobox).SelStart := Length(SearchStr);
(Sender as TCombobox).SelLength :=
(Length((Sender as TCombobox).Text) - Length(SearchStr));
end; // retVal CB_Err
end; // lastKey VK_BACK
// reset lastKey
lastKey := 0;
end;
// put the following lines in the OnKeyDown event of the TCombobox
procedure TForm1.AutoCompleteKeyDown(Sender: TObject; var Key: Word;
Shift: TShiftState);
begin
lastKey := Key;
end;
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