错误:找不到符号新的MethodChannel(flatterEngine.getDartExecutitor().ge

Question

我正试图用PlatformChannels从flutter导入Java代码，我在Ubuntu上，我收到了那个错误，也许是Java错误，我创建了我的项目

flutter create -a java batterylevel我关注这个链接上的文档https://flutter.dev/docs/development/platform-integration/platform-channels?tab=android-通道java选项卡

我有这个Java文件(与文档相同(

import android.content.Intent;
import android.content.IntentFilter;
import android.os.BatteryManager;
import android.os.Build.VERSION;
import android.os.Build.VERSION_CODES;
import android.os.Bundle;
import androidx.annotation.NonNull;
import io.flutter.embedding.android.FlutterActivity;
import io.flutter.embedding.engine.FlutterEngine;
import io.flutter.plugins.GeneratedPluginRegistrant;
public class MainActivity extends FlutterActivity {
private static final String CHANNEL = "samples.flutter.dev/battery";
@Override
public void configureFlutterEngine(@NonNull FlutterEngine flutterEngine) {
GeneratedPluginRegistrant.registerWith(flutterEngine);
new MethodChannel(flutterEngine.getDartExecutor().getBinaryMessenger(), CHANNEL)
.setMethodCallHandler(
(call, result) -> {
if (call.method.equals("getBatteryLevel")) {
int batteryLevel = getBatteryLevel();
if (batteryLevel != -1) {
result.success(batteryLevel);
} else {
result.error("UNAVAILABLE", "Battery level not available.", null);
}
} else {
result.notImplemented();
}
}
);
}
private int getBatteryLevel() {
int batteryLevel = -1;
if (VERSION.SDK_INT >= VERSION_CODES.LOLLIPOP) {
BatteryManager batteryManager = (BatteryManager) getSystemService(BATTERY_SERVICE);
batteryLevel = batteryManager.getIntProperty(BatteryManager.BATTERY_PROPERTY_CAPACITY);
} else {
Intent intent = new ContextWrapper(getApplicationContext()).
registerReceiver(null, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
batteryLevel = (intent.getIntExtra(BatteryManager.EXTRA_LEVEL, -1) * 100) /
intent.getIntExtra(BatteryManager.EXTRA_SCALE, -1);
}
return batteryLevel;
}
}

这个颤动代码(像文档一样(

import 'dart:async';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
class MyHomePage extends StatefulWidget {
const MyHomePage({
Key key,
}) : super(key: key);
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
static const platform = const MethodChannel('samples.flutter.dev/battery');
String _batteryLevel = 'Unknown battery level.';
Future<void> _getBatteryLevel() async {
String batteryLevel;
try {
final int result = await platform.invokeMethod('getBatteryLevel');
batteryLevel = 'Battery level at $result % .';
} on PlatformException catch (e) {
batteryLevel = "Failed to get battery level: '${e.message}'.";
}
setState(() {
_batteryLevel = batteryLevel;
});
}
@override
Widget build(BuildContext context) {
return Material(
child: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: [
RaisedButton(
child: Text('Get Battery Level'),
onPressed: _getBatteryLevel,
),
Text(_batteryLevel),
],
),
),
);
}
}

我在vscode OpenJDK11上有我的Java路径："Java.home"："/home/filipe/jdk1.8.0_111">

有人知道怎么了吗？也许是linux平台或者Java，或者是我的代码，希望你能帮助我，谢谢！！！

Answer 1

我发现自己有问题，我使用的是旧版本，而且我的通道不稳定，当我将我的flutter SDK升级到1.17版本并更改通道时，它可以工作。