flutter 在已有项目中引入flutter

官方教程
参考

创建flutter模块

在项目目录下执行

$ cd some/path/
$ flutter create -t module --org com.example my_flutter

flutter模块项目使用androidx

构建脚本

// MyApp/settings.gradle
include ':app'                                     // assumed existing content
setBinding(new Binding([gradle: this]))                                 // new
evaluate(new File(                                                      // new
  settingsDir.parentFile,                                               // new
  'my_flutter/.android/include_flutter.groovy'                          // new
))  

引入flutter模块

// MyApp/app/build.gradle

dependencies {
  implementation project(':flutter')
}

activity中引入flutter组件

    public void addFlutterView() {
        View flutterView = Flutter.createView(
                MainActivity.this,
                getLifecycle(),
                "route3"
        );
        FrameLayout.LayoutParams layout = new FrameLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
        ((ViewGroup) findViewById(R.id.layout)).addView(flutterView, layout);
    }

    public void addFlutterFragment() {
        log("addFlutterFragment " + new Date().getTime());
        FragmentTransaction tx = getSupportFragmentManager().beginTransaction();
        tx.replace(R.id.layout2, Flutter.createFragment("route1"));
        tx.commit();
    }
//route 在dart代码中接收window.defaultRouteName 根据不同显示不同的ui

//dart代码
void main() => runApp(getRootView());

Widget getRootView() {
  if ("route2" == window.defaultRouteName) {
    return MyApp2();
  } else {
    return MyApp();
  }
}

class MainActivity: FlutterActivity() {
  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    GeneratedPluginRegistrant.registerWith(this)
  }
  //activty中使用路由
  override fun createFlutterView(context: Context?): FlutterView {
    val flutterView = FlutterView(this, null, this.createFlutterNativeView())
    flutterView.setInitialRoute("route1")
    this.setContentView(flutterView)
    return flutterView
  }
}

加速

public class MixApp extends Application {
    @Override
    public void onCreate() {
        super.onCreate();
        Flutter.startInitialization(this);
    }
}
//或直接使用FlutterApplication

debug模式会慢些，release打包后加载很快的。