我正在尝试使用TextFormField中的值插入表中，但是每当我提交所有字段的值都为null时，insert语句就无法正常工作
这是包含表单的类，并且插入语句在下面为dao.InsertIntoItemList（itemList）。它的意思是跳回到页面，它将在表格中显示插入的项目，但我最终遇到此错误
I/flutter ( 7352): Inserted new item
E/flutter ( 7352): [ERROR:flutter/lib/ui/ui_dart_state.cc(148)] Unhandled Exception: InvalidDataException: Sorry, ItemList(id: null, itemName: null, noOfItems: null, unitPrice: null, checkListId: 1) cannot be used for that because:
E/flutter ( 7352): • itemName: This value was required, but isn't present
E/flutter ( 7352): • noOfItems: This value was required, but isn't present
E/flutter ( 7352): • unitPrice: This value was required, but isn't present
E/flutter ( 7352):
[38;5;248mE/flutter ( 7352): #0 VerificationContext.throwIfInvalid[39;49m
[38;5;248mE/flutter ( 7352): #1 InsertStatement._validateIntegrity[39;49m
[38;5;248mE/flutter ( 7352): #2 InsertStatement.insert[39;49m
E/flutter ( 7352): <asynchronous suspension>
[38;5;248mE/flutter ( 7352): #3 ItemListDao.insertItemList[39;49m
[38;5;248mE/flutter ( 7352): #4 _InputNewItemState.build.<anonymous closure>[39;49m
[38;5;244mE/flutter ( 7352): #5 _InkResponseState._handleTap[39;49m
[38;5;244mE/flutter ( 7352): #6 _InkResponseState.build.<anonymous closure>[39;49m
[38;5;244mE/flutter ( 7352): #7 GestureRecognizer.invokeCallback[39;49m
[38;5;244mE/flutter ( 7352): #8 TapGestureRecognizer._checkUp[39;49m
[38;5;244mE/flutter ( 7352): #9 TapGestureRecognizer.handlePrimaryPointer[39;49m
[38;5;244mE/flutter ( 7352): #10 PrimaryPointerGestureRecognizer.handleEvent[39;49m
[38;5;244mE/flutter ( 7352): #11 PointerRouter._dispatch[39;49m
[38;5;244mE/flutter ( 7352): #12 PointerRouter.route[39;49m
[38;5;244mE/flutter ( 7352): #13 GestureBinding.handleEvent[39;49m
[38;5;244mE/flutter ( 7352): #14 GestureBinding.dispatchEvent[39;49m
[38;5;244mE/flutter ( 7352): #15 GestureBinding._handlePointerEvent[39;49m
[38;5;244mE/flutter ( 7352): #16 GestureBinding._flushPointerEventQueue[39;49m
[38;5;244mE/flutter ( 7352): #17 GestureBinding._handlePointerDataPacket[39;49m
[38;5;244mE/flutter ( 7352): #18 _rootRunUnary (dart:async/zone.dart:1136:13)[39;49m
[38;5;244mE/flutter ( 7352): #19 _CustomZone.runUnary (dart:async/zone.dart:1029:19)[39;49m
[38;5;244mE/flutter ( 7352): #20 _CustomZone.runUnaryGuarded (dart:async/zone.dart:931:7)[39;49m
[38;5;244mE/flutter ( 7352): #21 _invoke1 (dart:ui/hooks.dart:263:10)[39;49m
[38;5;244mE/flutter ( 7352): #22 _dispatchPointerDataPacket (dart:ui/hooks.dart:172:5)[39;49m
E/flutter ( 7352):
I/flutter ( 7352): Moor: Sent SELECT * FROM item_lists WHERE check_list_id = ?; with args [1]
I/flutter ( 7352): Moor: Sent SELECT * FROM check_lists; with args []
I/flutter ( 7352): Moor: Sent SELECT * FROM item_lists WHERE check_list_id = ?; with args [1]
//以上是错误
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'itemlist.dart';
class EditItemList extends StatefulWidget {
final List<ItemList> listOfItems;
final String checkListName;
const EditItemList({Key key, this.checkListName, this.listOfItems})
: super(key: key);
@override
_EditItemListState createState() => _EditItemListState();
}
class _EditItemListState extends State<EditItemList> {
final key = GlobalKey<FormState>();
var itemName;
var noOfItems;
var unitPrice;
final FocusNode _itemNameFocus = FocusNode();
final FocusNode _noOfItemsFocus = FocusNode();
final FocusNode _unitPriceFocus = FocusNode();
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.checkListName),
),
body: SingleChildScrollView(
child: Form(
key: key,
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
ListTile(
title: TextFormField(
keyboardType: TextInputType.text,
focusNode: _itemNameFocus,
autofocus: true,
validator: (value) {
value == ""
? value = "This field can not be empty"
: value = null;
return value;
},
onSaved: (value) {
itemName = value;
},
decoration: InputDecoration(
labelText: 'Name of item',
labelStyle: TextStyle(fontWeight: FontWeight.bold),
hintText: 'eg: apple',
),
),
),
ListTile(
title: TextFormField(
keyboardType: TextInputType.number,
focusNode: _noOfItemsFocus,
autofocus: false,
validator: (value) {
value.trim().isEmpty
? value = "This field can not be empty"
: value = null;
return value;
},
onSaved: (value) {
noOfItems = value;
},
decoration: InputDecoration(
labelText: 'Number of items',
labelStyle: TextStyle(fontWeight: FontWeight.bold),
hintText: 'eg: 2',
),
),
),
ListTile(
title: TextFormField(
keyboardType: TextInputType.number,
focusNode: _unitPriceFocus,
autofocus: false,
validator: (value) {
value.trim().isEmpty
? value = "This field can not be empty"
: value = null;
return value;
},
onSaved: (value) {
unitPrice = value;
},
decoration: InputDecoration(
labelText: 'Price per item',
labelStyle: TextStyle(fontWeight: FontWeight.bold),
hintText: 'eg: 100',
),
),
),
ListTile(
title: RaisedButton(
child: Text('Add to List'),
onPressed: () {
if (this.key.currentState.validate()) {
this.key.currentState.save();
itemName = itemNameTextController.text ;
noOfItems = noOfItemsTextController.text;
unitPrice = unitPriceTextController.text;
final dao = Provider.of<ItemListDao>(context);
final itemList = ItemList(
id: null,
itemName: itemName,
noOfItems: noOfItems,
unitPrice: unitPrice,
checkListId: widget.checkListId,
);
dao.insertItemList(itemList);
debugPrint('Inserted new item');
Navigator.pop(context,itemList);
}
),
)
],
),
),
),
);
}
}
我如何处理此错误“类型'String'不是类型'int'的子类型”，我尝试将noOfitems强制转换为int并将unitPrice强制转换为int，因为它们都是IntColumn，但我仍然遇到相同的错误。请任何帮助，谢谢