opt.

lib/view/page/convert.dart

@@ -41,6 +41,13 @@ class _ConvertPageState extends State<ConvertPage>
     _s = S.of(context)!;
   }
 
+  @override
+  void dispose() {
+    super.dispose();
+    _textEditingController.dispose();
+    _textEditingControllerResult.dispose();
+  }
+
   @override
   Widget build(BuildContext context) {
     super.build(context);