Create a Custom Flutter Plugin with Android Support (Full Integration Guide)

$ sed to Flutter apps. flutter_custom_plugin/android/src/main/java/com/example/flutter_custom_plugin/FlutterCustomPlugin.java : Native Android implementation using Java (or Kotlin). pubspec.yaml : Plugin metadata and  supported platforms . You can switch to Kotlin by adding  --android-language kotlin  to your create command. 📡 Step 3: Define MethodChannel in Dart lib/flutter_custom_plugin.dart import 'package:flutter/services.dart'; class FlutterCustomPlugin {   static const MethodChannel _channel = MethodChannel('flutter_custom_plugin');   static Future<String?> getPlatformVersion() async {     final String? version = await _channel.invokeMethod('getPlatformVersion');     return version;   } } Explanation: We define a static  MethodChannel  named  'flutter_custom_plugin' . The  invokeMethod()  call sends a message to the platform side and waits for a response. Here we’re requesting  getPlatformVersion  from the Android side. 📱 Step 4: Implement Android Platform Code android/src/main/java/com/example/flutter_custom_plugin/FlutterCustomPlugin.java package com.example.flutter_custom_plugin; import androidx.annotation.NonNull; import io.flutter.embedding.engine.plugins.FlutterPlugin; import io.flutter.plugin.common.MethodCall; import io.flutter.plugin.common.MethodChannel; public class FlutterCustomPlugin implements FlutterPlugin, MethodChannel.MethodCallHandler {   private MethodChannel channel;   @Override   public void onAttachedToEngine(@NonNull FlutterPluginBinding binding) {     channel = new MethodChannel(binding.getBinaryMessenger(), "flutter_custom_plugin");     channel.setMethodCallHandler(this);   }   @Override   public void onMethodCall(@NonNull MethodCall call, @NonNull MethodChannel.Result result) {     if (call.method.equals("getPlatformVersion")) {       result.success("Android " + android.os.Build.VERSION.RELEASE);     } else {       result.notImplemented();     }   }   @Override   public void onDetachedFromEngine(@NonNull FlutterPluginBinding binding) {     channel.setMethodCallHandler(null);   } } Explanation: This Java class implements FlutterPlugin and MethodCallHandler. When  getPlatformVersion  is invoked from Dart, it returns the current Android OS version. If the method isn’t recognized,  notImplemented()  is called. 🧪 Step 5: Use the Plugin in a Flutter App Add the plugin to your  pubspec.yaml : dependencies:   flutter_custom_plugin:     path: ../flutter_custom_plugin Call it in your main app: import 'package:flutter/material.dart'; import 'package:flutter_custom_plugin/flutter_custom_plugin.dart'; void main() => runApp(MyApp()); class MyApp extends StatelessWidget {   @override   Widget build(BuildContext context) {     return MaterialApp(       home: PluginHome(),     );   } } class PluginHome extends StatefulWidget {   @override   _PluginHomeState createState() => _PluginHomeState(); } class _PluginHomeState extends State<PluginHome> {   String _platformVersion = 'Unknown';   @override   void initState() {     super.initState();     getPlatformVersion();   }   Future<void> getPlatformVersion() async {     final version = await FlutterCustomPlugin.getPlatformVersion();     setState(() {       _platformVersion = version ?? 'Failed to get version';     });   }   @override   Widget build(BuildContext context) {     return Scaffold(       appBar: AppBar(title: Text("Flutter Plugin Example")),       body: Center(child: Text('Running on: $_platformVersion')),     );   } } Explanation: We call our plugin’s  getPlatformVersion()  function inside  initState()  and display the Android OS version using a  Text  widget. 🔄 Testing the Plugin Run the example app using  flutter run . You should see the OS version returned from native Android code. If using Kotlin, ensure your plugin class uses  override fun  in a similar structure. 🧠 Final Thoughts Creating a custom Flutter plugin with Android support allows you to: Extend Flutter apps with native functionality Interact with Java/Kotlin APIs Reuse platform-specific  libraries in Dart apps Key Concepts  Recap: Use  MethodChannel  to bridge Dart and native Android Plugins let Flutter call Java/Kotlin functions Platform plugins follow the structure defined by  FlutterPlugin Have you tried writing your own Flutter plugin yet? Drop your ideas, doubts, or sample use cases in the comments—we’d love to help or feature your plugin!

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