Title: TEdit with auto-complete feature added
Question: An auto-complete feature can be added to a TEdit component by handling the keyUp event. This is a simple approach that gives complete control to the programmer.
Answer:
// See Delphi3000 article 1533 for auto-complete component
// To add auto-complete capability to a TEdit component
// 1) Declare a global TStringlist object
// 2) Create it on the form create event
// 3) Free it on the form destroy event
// 4) Add new entry to it on the TEdit exit event
// 5) Do the auto-complete on the TEdit keyUp event
// 6) Add a TCheckbox control for enable/disable
// If desired, initialize the list from a database, ini file etc.
procedure TForm1.FormCreate(Sender: TObject);
begin
listValues := TStringList.create;
listValues.sorted := true;
listValues.Duplicates := dupIgnore;
end;
procedure TForm1.FormDestroy(Sender: TObject);
begin
listValues.free;
end;
procedure TForm1.edtListExit(Sender: TObject);
begin
listValues.add(edtList.text);
end;
procedure TForm1.edtListKeyUp(Sender: TObject; var Key: Word;
Shift: TShiftState);
var
theText: string;
i, p: integer;
begin
if not ckbxList.checked then exit; // User can enable/disable
with edtList do
case key of
8, 13, 46, 37..40: ; // No backspace, enter, delete, or arrows
else
begin
// Search for unselected portion at start of text
p := selStart; // cursor position
theText := copy(text, 0, p); // Excludes searched portion
// Match entered text portion
for i := 0 to listValues.count-1 do
begin
// Keep case of listed item
if pos(upperCase(theText), upperCase(listValues[i]))=1 then
if compareText(theText, listValues[i]) begin
text := listValues[i];
selStart := p;
SelLength := length(text) - selStart;
break; // Match found, so quit search
end;
end; // for
end; // case
end; // with
end;