Error GlobalKey Flutter Detected, How solve? - flutter

Question

after a few weeks of using Flutter CRUD I was running normally and able to enter the database, but this time I encountered an error as shown below.
The error appears when I finish editing data, delete data. What do you think the solution to this problem is, friends?
Here I provide a snippet of my source code
listnasabah.dart
class ListNasabah {
ApiService apiService;
ListNasabah({this.apiService});
void getNasabah() {
apiService.getNasabah().then((nasabah) {
print(nasabah);
});
}
Widget createViewList() {
return SafeArea(
child: FutureBuilder(
future: apiService.getNasabah(),
builder: (BuildContext context, AsyncSnapshot<List<Nasabah>> snapshot) {
if (snapshot.hasError) {
return Center(
child: Text(
'Something wrong with message: ${snapshot.error.toString()}',
textAlign: TextAlign.center,
),
);
} else if (snapshot.connectionState == ConnectionState.done) {
List<Nasabah> nasabah = snapshot.data;
return nasabahListView(nasabah);
} else {
return Center(
child: CircularProgressIndicator(),
);
}
},
),
);
}
Widget nasabahListView(List<Nasabah> listnasabah) {
return Padding(
padding: const EdgeInsets.symmetric(vertical: 8.0, horizontal: 16.0),
child: ListView.builder(
shrinkWrap: true,
itemBuilder: (context, index) {
Nasabah nasabah = listnasabah[index];
return Padding(
padding: const EdgeInsets.only(top: 8.0),
child: Card(
child: Padding(
padding: const EdgeInsets.all(16.0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Text(
nasabah.nama_debitur,
style: Theme.of(context).textTheme.bodyText1,
),
Text(nasabah.alamat),
Text(nasabah.no_ktp),
Text(nasabah.no_telp),
Text(nasabah.no_selular),
Row(
mainAxisAlignment: MainAxisAlignment.end,
children: <Widget>[
ElevatedButton.icon(
onPressed: () {
showDialog(
context: context,
builder: (context) => AlertDialog(
title: Text('Hapus Data Nasabah'),
content: Text(
'Apakah anda yakin ingin menghapus data nasabah ini?'),
actions: [
TextButton(
child: Text('Yes'),
onPressed: () async {
apiService
.deleteNasabah(nasabah.id)
.then((value) => Navigator.of(
context)
.pushReplacement(
MaterialPageRoute(
builder: (context) =>
DataNasabah())));
})
],
),
);
},
style: ElevatedButton.styleFrom(
primary: Colors.red,
),
icon: Icon(Icons.delete),
label: Text('Hapus'),
),
SizedBox(
width: 5,
),
ElevatedButton.icon(
onPressed: () {
Navigator.push(
context,
MaterialPageRoute(
builder: (context) => DetailNasabah(
nasabah: nasabah,
),
),
);
},
icon: Icon(Icons.navigate_next),
label: Text(
'Detail',
),
)
],
)
],
),
),
),
);
},
itemCount: listnasabah.length,
),
);
}
}