var
sl: TStringList;
i: Integer;
s: String;
begin
sl := TStringList.Create;
try
sl.Text := ListBox1.Items.Text; // irgendein Inhalt in Stringlist kopieren
s := 'sl'; //gesuchter Text
for i := 0 to sl.Count - 1 do
begin
if Pos(s, sl[i]) > 0 then
ShowMessage('"' + s + '" in Zeile ' + IntToStr(i));
end;
finally
sl.Free;
end;
end;