我想在“NasabahDataTableSource”類中使用 setState 方法，但是當我在此類中使用 setState 時無法作業并且錯誤：沒有為“NasabahDataTableSource”類定義方法“setState”。
- “NasabahDataTableSource”來自“package:flutter_auth/screens/Menu/DataNasabah/datanasabah.dart”（“lib/screens/Menu/DataNasabah/datanasabah.dart”）。嘗試將名稱更正為現有方法的名稱，或定義名為“setState”的方法。setState(() { ^^^^^^^^
這是 mystatefullwidget。
class DataNasabah extends StatefulWidget {
@override
_DataNasabahState createState() => _DataNasabahState();
}
class _DataNasabahState extends State<DataNasabah> {
String nama_debitur = '';
List<Nasabah> _nasabah = [];
@override
void initState() {
super.initState();
_loadUserData();
_getNasabah();
}
_loadUserData() async {
SharedPreferences localStorage = await SharedPreferences.getInstance();
var user = jsonDecode(localStorage.getString('user'));
if (user != null) {
setState(() {
nama_debitur = user['nama_debitur'];
});
}
}
_getNasabah() {
NasabahService.getUser().then((nasabah) {
if (mounted) {
setState(() {
_nasabah = nasabah;
});
}
});
}
@override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.white,
appBar: AppBar(
title: Text('Data Nasabah'),
backgroundColor: Color(0xff151515),
// automaticallyImplyLeading: false,
),
body: SingleChildScrollView(
child: PaginatedDataTable(
rowsPerPage: 10,
columns: [
DataColumn(
label: Expanded(
child: Text(
'ID Nasabah',
textAlign: TextAlign.center,
)),
),
DataColumn(
label: Expanded(
child: Text(
'Nama Nasabah',
textAlign: TextAlign.center,
)),
),
DataColumn(
label: Expanded(
child: Text(
'Aksi',
textAlign: TextAlign.center,
)),
),
],
source: NasabahDataTableSource(userData: _nasabah, context: context),
),
),
);
}
}
我想在這個類中使用 setState 方法。但不能使用。我評論 setState 地方
class NasabahDataTableSource extends DataTableSource {
BuildContext context;
NasabahDataTableSource({this.context, this.userData});
final List<Nasabah> userData;
@override
DataRow getRow(int index) {
return DataRow.byIndex(
index: index,
cells: [
DataCell(Align(
alignment: Alignment.center,
child: Text(
"${userData[index].id}",
))),
DataCell(Align(
alignment: Alignment.center,
child: Text("${userData[index].nama_debitur}"),
)),
DataCell(
Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
IconButton(
icon: Icon(Icons.navigate_next),
color: Colors.blueAccent,
onPressed: () {
Navigator.push(
context,
MaterialPageRoute(
builder: (context) =>
DetailNasabah(
nasabah: userData[index],
),
),
);
},
),
IconButton(
icon: Icon(Icons.delete),
color: Colors.red,
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: () {
NasabahService.deleteUser(userData[index].id);
setState(() {
//Cann't use
});
})
],
),
);
},
)
],
),
),
],
);
}
我還沒有找到那個解決方案。請幫忙。
uj5u.com熱心網友回復：
你不能setState()沒有StatefulWidget. 我建議您使用Function來傳遞您的操作并通知使用setState(). 需要對您的代碼進行一些修改。
- 將
Function引數添加到您的NasabahDataTableSource.
Function onUserDeleted;
- 修改你的
NasabahDataTableSource建構式。
NasabahDataTableSource({required this.context,required this.userData,required this.onUserDeleted}); // modify your constructor
- 替換
setState為onUserDeletedinsideonPressed。
onUserDeleted(); // call onUserDeleted
//setState(() {
//Cann't use
//});
NasabahDataTableSource完整的代碼。
class NasabahDataTableSource extends DataTableSource {
BuildContext context;
Function onUserDeleted; // add onUserDeleted function
final List<Nasabah> userData;
NasabahDataTableSource({required this.context,required this.userData,required this.onUserDeleted}); // modify your constructor
@override
DataRow getRow(int index) {
return DataRow.byIndex(
index: index,
cells: [
DataCell(Align(
alignment: Alignment.center,
child: Text(
"${userData[index].id}",
))),
DataCell(Align(
alignment: Alignment.center,
child: Text("${userData[index].nama_debitur}"),
)),
DataCell(
Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
IconButton(
icon: Icon(Icons.navigate_next),
color: Colors.blueAccent,
onPressed: () {
Navigator.push(
context,
MaterialPageRoute(
builder: (context) =>
DetailNasabah(
nasabah: userData[index],
),
),
);
},
),
IconButton(
icon: Icon(Icons.delete),
color: Colors.red,
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: () {
NasabahService.deleteUser(userData[index].id);
onUserDeleted(); // call onUserDeleted
//setState(() {
//Cann't use
//});
})
],
),
);
},
)
],
),
),
],
);
}
DataNasabah通過添加onUserDeleted和呼叫修改您的源setState
source: NasabahDataTableSource(
userData: _nasabah,
context: context,
onUserDeleted:(){
setState((){}); // add setState
}),
DataNasabah完整的代碼。
class DataNasabah extends StatefulWidget {
@override
_DataNasabahState createState() => _DataNasabahState();
}
class _DataNasabahState extends State<DataNasabah> {
String nama_debitur = '';
List<Nasabah> _nasabah = [];
@override
void initState() {
super.initState();
_loadUserData();
_getNasabah();
}
_loadUserData() async {
SharedPreferences localStorage = await SharedPreferences.getInstance();
var user = jsonDecode(localStorage.getString('user'));
if (user != null) {
setState(() {
nama_debitur = user['nama_debitur'];
});
}
}
_getNasabah() {
NasabahService.getUser().then((nasabah) {
if (mounted) {
setState(() {
_nasabah = nasabah;
});
}
});
}
@override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.white,
appBar: AppBar(
title: Text('Data Nasabah'),
backgroundColor: Color(0xff151515),
// automaticallyImplyLeading: false,
),
body: SingleChildScrollView(
child: PaginatedDataTable(
rowsPerPage: 10,
columns: [
DataColumn(
label: Expanded(
child: Text(
'ID Nasabah',
textAlign: TextAlign.center,
)),
),
DataColumn(
label: Expanded(
child: Text(
'Nama Nasabah',
textAlign: TextAlign.center,
)),
),
DataColumn(
label: Expanded(
child: Text(
'Aksi',
textAlign: TextAlign.center,
)),
),
],
source: NasabahDataTableSource(
userData: _nasabah,
context: context,
onUserDeleted:(){
setState((){}); // add setState
}),
),
),
);
}
}
uj5u.com熱心網友回復：
你不能在 NasabahDataTableSource 中設定狀態，因為沒有擴展 StatefulWidget。只有有狀態的人才能設定狀態。但是您可以在無狀態下使用 getx 更改變數而不使用 setstate。
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