我是一个初学者，我通过添加createState()和admobe到原始文件进行了一些更改，但我一直被困在这个错误中:
lib/widgets/meal_item.dart:179:33: Error: The getter 'duration' isn't defined for the class '_MealItemState'.
- '_MealItemState' is from 'package:oumwalidmaindishes/widgets/meal_item.dart' ('lib/widgets/meal_item.dart').
Try correcting the name to the name of an existing getter, or defining a getter or field named 'duration'.
duration: duration,
^^^^^^^^
lib/widgets/meal_item.dart:180:36: Error: The getter 'preparation' isn't defined for the class '_MealItemState'.
- '_MealItemState' is from 'package:oumwalidmaindishes/widgets/meal_item.dart' ('lib/widgets/meal_item.dart').
Try correcting the name to the name of an existing getter, or defining a getter or field named 'preparation'.
preparation: preparation,
^^^^^^^^^^^
lib/widgets/meal_item.dart:181:31: Error: The getter 'people' isn't defined for the class '_MealItemState'.
- '_MealItemState' is from 'package:oumwalidmaindishes/widgets/meal_item.dart' ('lib/widgets/meal_item.dart').
Try correcting the name to the name of an existing getter, or defining a getter or field named 'people'.
people: people,
^^^^^^
lib/widgets/meal_item.dart:182:35: Error: The getter 'complexity' isn't defined for the class '_MealItemState'.
- '_MealItemState' is from 'package:oumwalidmaindishes/widgets/meal_item.dart' ('lib/widgets/meal_item.dart').
Try correcting the name to the name of an existing getter, or defining a getter or field named 'complexity'.
complexity: complexity))
^^^^^^^^^^
FAILURE: Build failed with an exception.
* Where:
Script 'C:srcflutterpackagesflutter_toolsgradleflutter.gradle' line: 1070
* What went wrong:
Execution failed for task ':app:compileFlutterBuildDebug'.
> Process 'command 'C:srcflutterbinflutter.bat'' finished with non-zero exit value 1
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
* Get more help at https://help.gradle.org
BUILD FAILED in 17s
Exception: Gradle task assembleDebug failed with exit code 1
当我试图删除这一行错误解决，但其他出现:
@override
State<MealItem> createState() => _MealItemState();
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:google_mobile_ads/google_mobile_ads.dart';
import 'package:oumwalidmaindishes/models/ad_helper.dart';
import 'package:provider/provider.dart';
import '../providers/favorite.dart';
import './meal_info.dart';
import '../screens/meal_detail_screen.dart';
import '../models/meal.dart';
const int maxFailedLoadAttempts = 3;
class MealItem extends StatefulWidget {
final String id;
final String imageUrl;
final String title;
final int preparation;
final int duration;
final Complexity complexity;
final int people;
const MealItem({
Key? key,
required this.id,
required this.imageUrl,
required this.people,
required this.title,
required this.complexity,
required this.duration,
required this.preparation,
}) : super(key: key);
@override
State<MealItem> createState() => _MealItemState();
}
class _MealItemState extends State<MealItem> {
int _interstitialLoadAttempts = 0;
InterstitialAd? _interstitialAd;
void _createInterstitialAd() {
InterstitialAd.load(
adUnitId: AdHelper.interstitialAdUnitId,
request: AdRequest(),
adLoadCallback: InterstitialAdLoadCallback(
onAdLoaded: (InterstitialAd ad) {
_interstitialAd = ad;
_interstitialLoadAttempts = 0;
},
onAdFailedToLoad: (LoadAdError error) {
_interstitialLoadAttempts += 1;
_interstitialAd = null;
if (_interstitialLoadAttempts <= maxFailedLoadAttempts) {
_createInterstitialAd();
}
},
),
);
}
void _showInterstitialAd() {
if (_interstitialAd != null) {
_interstitialAd!.fullScreenContentCallback = FullScreenContentCallback(
onAdDismissedFullScreenContent: (InterstitialAd ad) {
ad.dispose();
_createInterstitialAd();
},
onAdFailedToShowFullScreenContent: (InterstitialAd ad, AdError error) {
ad.dispose();
_createInterstitialAd();
},
);
_interstitialAd!.show();
}
}
@override
void initState() {
super.initState();
_createInterstitialAd();
}
@override
void dispose() {
super.dispose();
_interstitialAd?.dispose();
}
void selectMeal(BuildContext context) {
_showInterstitialAd();
Navigator.of(context)
.pushNamed(
MealDetailScreen.routeName,
arguments: widget.id,
)
.then((result) {
if (result != null) {
// removeItem(result);
}
});
}
@override
Widget build(BuildContext context) {
final favMeals = Provider.of<Favorite>(context);
return InkWell(
onTap: () => selectMeal(context),
child: Card(
shape:
RoundedRectangleBorder(borderRadius: BorderRadius.circular(20)),
elevation: 10,
margin: const EdgeInsets.all(15),
child: Column(
children: [
Stack(
children: [
ClipRRect(
borderRadius: BorderRadius.circular(20),
child: Image.asset(
widget.imageUrl,
height: 250,
width: double.infinity,
fit: BoxFit.cover,
),
),
Positioned(
bottom: 0,
left: 0,
child: Container(
decoration: const BoxDecoration(
borderRadius:
BorderRadius.only(topRight: Radius.circular(20), bottomLeft: Radius.circular(20)),
color: Color(0xfff2f2f2),),
width: 300,
// color: Colors.black45,
padding: const EdgeInsets.symmetric(
horizontal: 30,
vertical: 5,
),
child: Text(
widget.title,
style: const TextStyle(
color: Colors.black87,
fontSize: 22,
),
softWrap: true,
overflow: TextOverflow.fade,
),
),
),
Positioned(
bottom: 10,
right: 5,
child: SizedBox(
width: 50,
height: 50,
child: FittedBox(
child: FloatingActionButton(
heroTag: null,
backgroundColor: Colors.white,
onPressed: () {
favMeals.toggleFavorite(widget.id);
},
child: favMeals.isMealFavorite(widget.id)
? const Icon(
Icons.favorite_rounded,
color: Colors.pink,
)
: const Icon(Icons.favorite_border_rounded)),
),
),
)
],
),
Padding(
padding: const EdgeInsets.all(20.0),
child: MealInfo(
duration: duration,
preparation: preparation,
people: people,
complexity: complexity))
],
),
));
}
}
要访问_MealItemState中的duration，您需要使用小部件属性:
this.widget.duration