Rechercher et remplacer du texte dans un Richedit

// Sans utiliser TReplaceDialog

function Search_And_Replace(RichEdit: TRichEdit; SearchText, ReplaceText: string): boolean;
var
startpos, position, endpos: integer;

begin
startpos := 0;
with RichEdit do
begin
endpos := Length(RichEdit.Text);
Lines.BeginUpdate;
while FindText(SearchText, startpos, endpos, [stMatchCase])<>-1 do
begin
endpos := Length(RichEdit.Text) - startpos;
position := FindText(SearchText, startpos, endpos, [stMatchCase]);
Inc(startpos, Length(SearchText));
SetFocus;
SelStart := position;
SelLength := Length(SearchText);
richedit.clearselection;
SelText := ReplaceText;
end;
Lines.EndUpdate;
end;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
Search_And_Replace(Richedit1,'OldText','NewText');
end;