Title: A "Smart Combo" match search
Question: How to make to your combo box searches for the best match when you are typing ?
Answer:
now here is a method to force the combo box to search for the best match for the input you
are typing:
// define this variable
LastKeyPressed: Word;
procedure TForm1.ComboBox1KeyDown(Sender: TObject; var Key: Word;
Shift: TShiftState);
begin
LastKeyPressed := Key; // save the last key you pressed
end;
procedure TForm1.ComboBox1Change(Sender: TObject);
Var
ComboText : String;
NewComboText : String;
matchindex : integer;
begin
ComboText := ComboBox1.Text;
// give the user the ability to delete the text;
if (LastKeyPressed = VK_DELETE) OR (LastKeyPressed = 8 ) then begin
LastKeyPressed := 0;
end
else begin
if ComboBox1.SelStart length (ComboText) then // to make sure that in this moment the user is just beginning
to type
// do nothing here , because he can type any thing he want in the middle of the text
else begin
// find the match
matchindex := sendmessage ( ComboBox1.Handle, CB_FINDSTRING , -1,
LPARAM(ComboText) ) ;
if matchindex = 0 then begin
ComboBox1.ItemIndex := matchindex ;
NewComboText := ComboBox1.Text;
// highlight the other part of the text:
sendmessage ( ComboBox1.Handle, CB_SETEDITSEL , 0,
MAKELPARAM(length(ComboText) , word(-1) ));
end;
end;
end;
// NOTE: This code was tested on delphi 4, Windows NT workstation 4