android - FlutterActivity MethodChannel和FlutterView，腾讯大牛教你自己写Android第三方库

在Android平台上，Flutter提供了一个名为FlutterActivity的类，用于嵌入Flutter在现有的Android应用中。如果你想要与Flutter交互，可以使用MethodChannel来进行方法调用。

以下是一个简单的例子，展示如何在Android中创建一个MethodChannel，并在Flutter端调用Android的方法：

1. 在Android的FlutterActivity中注册MethodChannel并设置一个处理方法。

import io.flutter.embedding.android.FlutterActivity;
import io.flutter.embedding.engine.FlutterEngine;
import io.flutter.plugin.common.MethodCall;
import io.flutter.plugin.common.MethodChannel;
 
public class MainActivity extends FlutterActivity {
    private static final String CHANNEL = "samples.flutter.dev/battery";
 
    @Override
    public void configureFlutterEngine(FlutterEngine flutterEngine) {
        MethodChannel methodChannel = new MethodChannel(flutterEngine.getDartExecutor(), CHANNEL);
        methodChannel.setMethodCallHandler(
            (call, result) -> {
                // 处理来自Flutter的方法调用
                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() {
        // 实现获取电池电量的逻辑
        return 100; // 示例返回100%
    }
}

2. 在Flutter端，通过MethodChannel调用Android的getBatteryLevel方法。

import 'package:flutter/services.dart';
 
class BatteryLevel {
  static const MethodChannel _channel =
      const MethodChannel('samples.flutter.dev/battery');
 
  static Future<int> get batteryLevel async {
    final int batteryLevel = await _channel.invokeMethod('getBatteryLevel');
    return batteryLevel;
  }
}
 
void main() {
  runApp(MyApp());
}
 
class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('Battery Level'),
        ),
        body: Center(
          child: FutureBuilder<int>(
            future: BatteryLevel.batteryLevel,
            builder: (context, snapshot) {
              if (snapshot.connectionState == ConnectionState.done) {