FlutterAndroid导入Unity项目踩坑笔记

Flutter Android 导入Unity项目时我遇到了一些问题，我使用Flutter_unity_view_widget 组件来进行导入。

Flutter 版本

Flutter 2.5.3 • channel unknown • unknown source
Framework • revision 18116933e7 (10 months ago) • 2021-10-15 10:46:35 -0700
Engine • revision d3ea636dc5
Tools • Dart 2.14.4

导入步骤如下：

1.首先安装 Flutter_unity_view_widget

去 pubspec.yaml 的dependencies下添加

dependencies:
  flutter:
    sdk: flutter

  flutter_unity_widget: ^4.2.0

然后去项目根目录输入 对pub进行下载

flutter pub get

2.在项目根目录创建unity文件夹，并将Unity的项目存入文件夹下

然后打开 UnityHub 并导入这个项目

打开Unity项目后

1. 在 File > Build Settings > Player Settings 然后选择 Configuration :

   • 将 Scripting Backend 为 IL2CPP
   • 将 Target Architectures，勾选 ARMv7 和 ARM64

1. 然后选择 Flutter 菜单，选择 Export Android 导出 Android项目，项目将导出到 android/unityLibrary 下

注意：此时你的android 项目已经集成了 unity 项目了，并自动对gradle进行的一些设置

3.做完以上配置后还需要修改一些参数：

1. 在 android/app/build.gradle 下将 minSdkVersion 设置为和 UnityLibrary 下的 build.gradle 的minSdkVersion 一致
2. 在 android/local.properties 下设置 ndk.dir=/你Unity的Ndk的目录
3. 修改 android/build.gradle 下的 repositories 的镜像地址为阿里云镜像url

buildscript {
    ext.kotlin_version = '1.3.50'
    repositories {
        // google()
        // mavenCentral()
        maven{ url 'https://maven.aliyun.com/repository/google' }
        maven{ url 'https://maven.aliyun.com/repository/jcenter' }
        maven{ url 'https://maven.aliyun.com/repository/public'}
        maven{ url 'https://maven.aliyun.com/repository/gradle-plugin'}
    }

    dependencies {
        classpath 'com.android.tools.build:gradle:4.1.0'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
    }
}

allprojects {
    repositories {
        flatDir {
            dirs "${project(':unityLibrary').projectDir}/libs"
        }
        // google()
        // mavenCentral()
        maven{ url 'https://maven.aliyun.com/repository/google' }
        maven{ url 'https://maven.aliyun.com/repository/jcenter' }
        maven{ url 'https://maven.aliyun.com/repository/public'}
        maven{ url 'https://maven.aliyun.com/repository/gradle-plugin'}
    }
}

然后如果有报 IL2Capp 相关的报错，需要你注视一下三条信息（这玩意儿折磨了我三天，艹）

然后您就可以运行调试，可能会有黄色的关于IL2Cpp的警告提示，可以忽略，第一次构建的时候时间会比较长，耐心等待一下，构建后就可以成功运行了。

4.写FlutterUnityViewWiget 测试代码

然后您可以导入下面的Flutter Demo代码导入到 main.dart 入口文件中进行测试

import 'package:flutter/material.dart';
import 'package:flutter_unity_widget/flutter_unity_widget.dart';

void main() => runApp(MyAppFlutter());

class MyAppFlutter extends StatefulWidget {
  @override
  _MyAppFlutterState createState() => _MyAppFlutterState();
}

class _MyAppFlutterState extends State<MyAppFlutter> {
  static final GlobalKey<ScaffoldState> _scaffoldKey =
    GlobalKey<ScaffoldState>();
  late UnityWidgetController _unityWidgetController;
  double _sliderValue = 0.0;
  
  @override
  void initState() {
    super.initState();
  }
  
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        key: _scaffoldKey,
        appBar: AppBar(
          title: const Text('Unity Flutter Demo'),
        ),
        body: Card(
          margin: const EdgeInsets.all(8),
          clipBehavior: Clip.antiAlias,
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(20.0),
          ),
          child: Stack(
            children: <Widget>[
              UnityWidget(
                onUnityCreated: onUnityCreated,
                onUnityMessage: onUnityMessage,
                // onUnitySceneLoaded: onUnitySceneLoaded,
                fullscreen: false,
              ),
            ],
          ),
        ),
      ),
    );
  }
  
  // Communcation from Flutter to Unity
  void setRotationSpeed(String speed) {
    _unityWidgetController.postMessage(
      'Cube',
      'SetRotationSpeed',
      speed,
    );
  }
  
  // Communication from Unity to Flutter
  void onUnityMessage(message) {
    print('Received message from unity: ${message.toString()}');
  }
  
  // Callback that connects the created controller to the unity controller
  void onUnityCreated(controller) {
    this._unityWidgetController = controller;
  }
  
  // Communication from Unity when new scene is loaded to Flutter
  void onUnitySceneLoaded(SceneLoaded sceneInfo) {
    print('Received scene loaded from unity: ${sceneInfo.name}');
    print('Received scene loaded from unity buildIndex: ${sceneInfo.buildIndex}');
  }
  
}

5.测试效果