Value change but UI don't - flutter

Question

I want to show a button only if the new value is different from the old one. But its not working, the button isn't showing
class ViewPatientPage extends StatefulWidget {
final int status;
final String name;
const ViewPatientPage({required this.status, required this.name, super.key});
#override
State<ViewPatientPage> createState() => _ViewPatientPageState();
}
class _ViewPatientPageState extends State<ViewPatientPage> {
String name = '';
#override
void initState() {
super.initState();
name = widget.name;
}
SizedBox space() {
return const SizedBox(height: 15);
}
#override
Widget build(BuildContext context) {
return GestureDetector(
onTap: () {
FocusManager.instance.primaryFocus?.unfocus();
},
child: Scaffold(
appBar: AppBar(
actions: [
(name != widget.name) ? TextButton(
onPressed: () {},
child: const Text(
'Editar',
style: TextStyle(color: Colors.white),
)): const SizedBox.shrink()
],
),
body: Padding(
padding: const EdgeInsets.symmetric(horizontal: 10),
child: Column(
children: [
space(),
TextFormField(
initialValue: widget.name,
// keyboardType: keyboardType,
validator: (val) {
if (val.toString().isEmpty || val == null || val == '') {
return 'Fill field';
}
return null;
},
decoration: InputDecoration(
label: const Text('Name'),
contentPadding: const EdgeInsets.symmetric(horizontal: 20),
border: OutlineInputBorder(
borderSide: const BorderSide(color: Colors.black),
borderRadius: BorderRadius.circular(20))),
onChanged: (value) {
name = value.trim();
print(name);
print('widget ${widget.name}');
},
// inputFormatters: inputFormatters,
),
space(),
],
),
),
),
);
}
}
#random text to satisfy the site's rules flutter code vscode button textButton
random text to satisfy the site's rules flutter code vscode button textButton
random text to satisfy the site's rules flutter code vscode button textButton
random text to satisfy the site's rules flutter code vscode button textButton
random text to satisfy the site's rules flutter code vscode button textButton
random text to satisfy the site's rules flutter code vscode button textButton

Answer 1

You need to call setState() in onChanged.
Something like:
onChanged: (value) {
setState(() {
name = value.trim();
});
print(name);
print('widget ${widget.name}');
},

Answer 2

Call setState inside onChanged function
setState(() { name = value.trim(); });

Answer 3

To update the UI, you have to a call a setState() in the onChanged: (value) {}
setState(()
{
...
});