Flutter 和 Android 混合开发（flutterBo

flutter源码依赖简单demo(名字为onlyone)：
flutter混合开发中，会有flutter module和flutter plugin

1.分别创建Flutter module和Flutter plugin

2.Flutter module的pubspec.yaml中引入flutter plugin依赖

  only_one_flutter_plugin:
    path: /Users/xufangzhen/FlutterProjects/only_one_flutter_plugin

3.将Flutter Module import进android工程

android工程中修改点如下：
1.settings.gradle文件中创建对flutter module进行评估，并引入

setBinding(new Binding([gradle: this]))
evaluate(new File(settingsDir, './only_one_flutter_module/.android/include_flutter.groovy'))

include ':only_one_flutter_module'
project(':only_one_flutter_module').projectDir = new File('xxx/only_one_flutter_module')

4.在app module中的build.gradle中引入

implementation project(path: ':flutter')
implementation project(path: ':only_one_flutter_plugin')

可能会遇到问题：

1. 使用flutter v1.12，需要升级android的target sdk 为28及以上
2. 如果你的工程没有使用androidx，那么你需要将flutter mo，dule中的pubspec.yaml文件里androidX: true去掉。
3. setting include工程的工程 only_one_flutter_module后，原android工程无法断点调试，只需要将include的名字和路径改成only_one_flutter_module的父目录即可。

引入闲鱼的 flutter_boost

flutter_boost引入主要是解决native跳flutter重复创建flutter engine引题内存等问题，具体可以去闲鱼博客上了解。
到了flutter sdk是1.12.x，flutter engine可以复用了，具体还没看

具体使用如下：

在flutter plugin中pubspec.yarml的，使用引入flutter_boost
查看git上的介绍，不支持android x，flutter sdk是1.12的，使用以下配置

  flutter_boost:
    git:
      url: 'https://github.com/alibaba/flutter_boost.git'
      ref: 'task/task_v1.12.13_support_hotfixes'

flutter plugin 的 android工程的app的build.gradle中添加

    api project(path: ':flutter_boost')

在flutter module的main()方法中，调用plugin的初始化方法

return MaterialApp(
      builder: OnlyOnePlugin.init({
        'one': (pageName, params, _) {
          return OnePage();
        },
        'twoPage': (pageName, params, _) {
          return TwoPage();
        },
      }),
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );

在flutter plugin的lib下创建的OnlyOnePlugin类，
并增加注册、跳转和关闭方法

class OnlyOnePlugin {
  static TransitionBuilder init(Map<String, PageBuilder> builders) {
    FlutterBoost.singleton.registerPageBuilders(builders);
    return FlutterBoost.init();
  }

  static Future<Map<dynamic, dynamic>> openPage(String pageName,
      {Map<dynamic, dynamic> data, Map<dynamic, dynamic> exts}) async {
    return FlutterBoost.singleton
        .open(changeToRouterUrl(pageName), urlParams: data, exts: exts);
  }

  static Future<bool> closePage(BuildContext context,
      {Map<String, dynamic> data, bool animate}) async {
    if (null == context) return Future.value(false);
    String uniqueId = BoostContainer.of(context)?.settings?.uniqueId ?? "";
    return FlutterBoost.singleton.close(uniqueId, result: data, exts: null);
  }

  static const MethodChannel _channel =
      const MethodChannel('only_one_flutter_plugin');

  static Future<String> get platformVersion async {
    final String version = await _channel.invokeMethod('getPlatformVersion');
    return version;
  }

 ……
}

在flutter plugin的android工程中，进行初始化、容器、bridge等工作开发

初始化：

在application的create方法中调用初始化方法

    public static void initBoost(Application application) {
        FlutterBoost.BoostLifecycleListener boostLifecycleListener = new FlutterBoost.BoostLifecycleListener() {
            @Override
            public void beforeCreateEngine() {
            }

            @Override
            public void onEngineCreated() {
            }

            @Override
            public void onPluginsRegistered() {
            }

            @Override
            public void onEngineDestroy() {
            }
        };


        INativeRouter router = new INativeRouter() {
            @Override
            public void openContainer(Context context, String url, Map<String, Object> urlParams, int requestCode, Map<String, Object> exts) {
                openPage(context, url, urlParams, requestCode, exts);
            }
        };

        Platform platform = new FlutterBoost
                .ConfigBuilder(application, router)
                .isDebug(isDebug)
                .whenEngineStart(FlutterBoost.ConfigBuilder.ANY_ACTIVITY_CREATED)
                .renderMode(FlutterView.RenderMode.texture)
                .lifecycleListener(boostLifecycleListener)
                .build();
        FlutterBoost.instance().init(platform);
    }

遇到问题：

1. FlutterBoostPlugin not register yet
   如果出现上面的问题，说明flutter module的android工程里，GeneratedPluginRegistrant
   无法自动生成。com.idlefish.flutterboost.FlutterBoostPlugin.registerWith(shimPluginRegistry.registrarFor("com.idlefish.flutterboost.FlutterBoostPlugin"));
   早期遇到这个问题需要手动注册，现在flutter_boost已经修复

容器：

可以自己写个Flutter容器，加载FlutterBoost里的flutterFragment
再带个启动方法，（用路由的结合下路由，这里略去）

    public static void launch(Activity context, String pageName, JSONObject param, int requestCode) {
        Intent intent = new Intent(context, OnlyFlutterActivity.class);
        intent.putExtra(PAGE_NAME_KEY, pageName);
        intent.putExtra(ROUTER_PARAM_KEY, param);
        context.startActivityForResult(intent, requestCode);
    }

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.only_flutter_activity);
        String pageName = getIntent().getStringExtra(PAGE_NAME_KEY);
        HashMap params = (HashMap) getIntent().getSerializableExtra(ROUTER_PARAM_KEY);

        mFragment = new FlutterFragment.NewEngineFragmentBuilder().url(pageName).params(params).build();
        getSupportFragmentManager().beginTransaction()
                .replace(R.id.fragment_stub, mFragment)
                .commit();
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        mFragment.onActivityResult(requestCode, resultCode, data);
    }

其中pageName就是在flutter module里注册进去的页面名。

return MaterialApp(
      builder: OnlyOneFlutterPlugin.init({
        'onePage': (pageName, params, _) {
          print("params = " + params.toString());
          return OnePage(title: "标题1");
        },
        'twoPage': (pageName, params, _) {
          return TwoPage(title: "标题2");
        },
      }),
……

上面看到已经看到了native跳flutter

flutter跳flutter或者flutter跳native只需要调用flutter plugin lib下OnlyOneFlutterPlugin的openPage方法即可

//flutter跳flutter
OnlyOneFlutterPlugin.openPage("twoPage", data: params);

//flutter跳native
OnlyOneFlutterPlugin.openPage("MainActivity", data: params);

flutter端不管跳flutter还是native都调用了
FlutterBoost.singleton.open方法，最终会触发下面这个在初始化时的回调。

  INativeRouter router = new INativeRouter() {
            @Override
            public void openContainer(Context context, String url, Map<String, Object> urlParams, int requestCode, Map<String, Object> exts) {
                openPage(context, url, urlParams, requestCode, exts);
            }
        };

我们只需要在openPage的方法中写下时跳native页面还是flutter页面即可。
这里简单的示意下，正确的做法还是要在路由器的拦截器方法里写

    static void openPage(Context context, String url, Map<String, Object> urlParams, int requestCode, Map<String, Object> exts) {
        if ("onePage".equals(url) || "twoPage".equals(url)) {
            ……
            OnlyFlutterActivity.launch ……
        } else {
            ……
            AppRouter.launch ……
        }
    }