[英]Flutter: Unhandled Exception: MissingPluginException(No implementation found for method on channel)
[英]Unhandled Exception: MissingPluginException(No implementation found for method scanBarcode on channel flutter_barcode_scanner)
我試圖通過以下方式創建條形碼掃描儀: https://pub.dev/packages/flutter_barcode_scanner/install 。
當我運行我的代碼時,我得到了這個錯誤:
E/flutter ( 9248): [ERROR:flutter/lib/ui/ui_dart_state.cc(209)] Unhandled Exception: MissingPluginException(No implementation found for method scanBarcode on channel flutter_barcode_scanner)
E/flutter ( 9248): #0 MethodChannel._invokeMethod (package:flutter/src/services/platform_channel.dart:165:7)
E/flutter ( 9248): <asynchronous suspension>
E/flutter ( 9248): #1 FlutterBarcodeScanner.scanBarcode (package:flutter_barcode_scanner/flutter_barcode_scanner.dart:43:9)
E/flutter ( 9248): <asynchronous suspension>
E/flutter ( 9248): #2 _MyAppState.scanBarcodeNormal (package:styleupapp1/main.dart:46:24)
E/flutter ( 9248): <asynchronous suspension>
E/flutter ( 9248):
這是我的代碼:
import 'dart:async';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_barcode_scanner/flutter_barcode_scanner.dart';
void main() => runApp(MyApp());
class MyApp extends StatefulWidget {
@override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
String _scanBarcode = 'Unknown';
@override
void initState() {
super.initState();
}
Future<void> startBarcodeScanStream() async {
FlutterBarcodeScanner.getBarcodeStreamReceiver(
'#ff6666', 'Cancel', true, ScanMode.BARCODE)!
.listen((barcode) => print(barcode));
}
Future<void> scanQR() async {
String barcodeScanRes;
try {
barcodeScanRes = await FlutterBarcodeScanner.scanBarcode(
'#ff6666', 'Cancel', true, ScanMode.QR);
print(barcodeScanRes);
} on PlatformException {
barcodeScanRes = 'Failed to get platform version.';
}
//barcode scanner flutter ant
setState(() {
_scanBarcode = barcodeScanRes;
});
}
Future<void> scanBarcodeNormal() async {
String barcodeScanRes;
try {
barcodeScanRes = await FlutterBarcodeScanner.scanBarcode(
'#ff6666', 'Cancel', true, ScanMode.BARCODE);
print(barcodeScanRes);
} on PlatformException {
barcodeScanRes = 'Failed to get platform version.';
}
if (!mounted) return;
setState(() {
_scanBarcode = barcodeScanRes;
});
}
//barcode scanner flutter ant
@override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
home: Scaffold(
appBar: AppBar(title: const Text('Barcode Scanner')),
body: Builder(builder: (BuildContext context) {
return Container(
alignment: Alignment.center,
child: Flex(
direction: Axis.vertical,
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
ElevatedButton(
onPressed: () => scanBarcodeNormal(),
child: const Text('Barcode scan')),
ElevatedButton(
onPressed: () => scanQR(),
child: const Text('QR scan')),
ElevatedButton(
onPressed: () => startBarcodeScanStream(),
child: const Text('Barcode scan stream')),
Text('Scan result : $_scanBarcode\n',
style: const TextStyle(fontSize: 20))
]));
})));
}
}
有沒有人遇到過這個錯誤? 我不知道該怎么做我嘗試了不同的方法和包,但每個人都給了我同樣的錯誤。 這對我來說很重要,謝謝你的回答。
我問過一次,但沒有人回答。 我真的需要修復它。
修改所有引用FlutterFragmentActivity
為FlutterActivity
Java:
public class MainActivity extends FlutterActivity
或者對於 Kotlin:
class MainActivity: FlutterActivity()
更多信息: 插件 Api 遷移
希望,它會工作。
吃睡眠代碼重復。
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