Making Flutter C/C++ interop example work
1,939
You have to import /path/to/project/native_add/example/lib/native_add.dart
, because you have imported native_add plugin instead.
Author by
kakyo
Updated on December 14, 2022Comments
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kakyo over 1 year
I'm learning Flutter-C/C++ interop according to the official example. However, the code I wrote according to the tutorial doesn't compile. There must be some misunderstanding but I have no idea where. Step 1 and 2 seem easy enough and I don't have errors, but after Step 3, the generated example code
/path/to/project/native_add/example/lib/main.dart
looks like thisimport 'package:flutter/material.dart'; import 'dart:async'; import 'package:flutter/services.dart'; import 'package:native_add/native_add.dart'; void main() => runApp(MyApp()); class MyApp extends StatefulWidget { @override _MyAppState createState() => _MyAppState(); } class _MyAppState extends State<MyApp> { String _platformVersion = 'Unknown'; @override void initState() { super.initState(); initPlatformState(); } // Platform messages are asynchronous, so we initialize in an async method. Future<void> initPlatformState() async { String platformVersion; // Platform messages may fail, so we use a try/catch PlatformException. try { platformVersion = await NativeAdd.platformVersion; } on PlatformException { platformVersion = 'Failed to get platform version.'; } // If the widget was removed from the tree while the asynchronous platform // message was in flight, we want to discard the reply rather than calling // setState to update our non-existent appearance. if (!mounted) return; setState(() { _platformVersion = platformVersion; }); } @override Widget build(BuildContext context) { return MaterialApp( home: Scaffold( appBar: AppBar( title: const Text('Plugin example app'), ), body: Center( child: Text('1 + 2 == ${nativeAdd(1, 2)}'), ), ), ); } }
/path/to/project/native_add/example/lib/native_add.dart
looks like thisimport 'dart:ffi'; // For FFI import 'dart:io'; // For Platform.isX // Define physical lib: the lib binary file to integrate final DynamicLibrary nativeAddLib = Platform.isAndroid ? DynamicLibrary.open("libnative_add.so") : DynamicLibrary.open("native_add.framework/native_add"); // Retrieve exportable API in the lib binary final int Function(int x, int y) nativeAdd = nativeAddLib .lookup<NativeFunction<Int32 Function(Int32, Int32)>>("native_add") .asFunction();
Running
main.dart
gives me errors:Launching lib/main.dart on iPhone 11 Pro Max in debug mode... Compiler message: lib/main.dart:52:35: Error: Method not found: 'nativeAdd'. child: Text('1 + 2 == ${nativeAdd(1, 2)}'), ^^^^^^^^^ lib/main.dart:52:35: Error: The method 'nativeAdd' isn't defined for the class '_MyAppState'. - '_MyAppState' is from 'package:native_add_example/main.dart' ('lib/main.dart'). Try correcting the name to the name of an existing method, or defining a method named 'nativeAdd'. child: Text('1 + 2 == ${nativeAdd(1, 2)}'), ^^^^^^^^^ Compiler failed on /Users/me/Desktop/_dev/playground/flutter/flutter_firstflutterapp_part2/native_add/example/lib/main.dart Error launching application on iPhone 11 Pro Max.
Where am I wrong?
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TejaDroid about 4 yearsHi, Can you please provide github repository of native_add, I have same requirement so I need to learn C/C++ support in flutter
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