Flutter开发之——Android-Flutter添加到Activity，Android高级

在Android原生项目中集成Flutter模块通常涉及以下步骤：

1. 在项目的settings.gradle文件中添加Flutter模块路径：

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

2. 在主Application类中初始化Flutter引擎，并获取Flutter的首活动（FlutterActivity或FlutterFragment）的类引用。
3. 在需要展示Flutter界面的Activity中启动FlutterActivity或FlutterFragment。

以下是一个简化的示例代码：

import io.flutter.embedding.android.FlutterActivity;
import io.flutter.embedding.engine.FlutterEngine;
import io.flutter.plugin.common.PluginRegistry;
 
public class MyApplication extends Application implements PluginRegistry.PluginRegistrantCallback {
 
    @Override
    public void onCreate() {
        super.onCreate();
        // Initialize Flutter engine only once.
        FlutterEngine flutterEngine = new FlutterEngine(this);
        flutterEngine.getDartExecutor().executeDartEntrypoint(
                DartExecutor.DartEntrypoint.createDefault()
        );
        FlutterEngineCache.getInstance().put("my_engine_id", flutterEngine);
    }
 
    @Override
    public void registerWith(PluginRegistry registry) {
        // Register plugins and other components here if needed.
    }
}
 
public class MainActivity extends AppCompatActivity {
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
 
        // Start Flutter activity with desired FlutterEngine.
        Intent intent = new Intent(this, FlutterActivity.class);
        intent.putExtra("flutterEngineId", "my_engine_id");
        startActivity(intent);
    }
}

在这个例子中，我们创建了一个Flutter引擎并将其存储在FlutterEngineCache中，然后通过Intent在MainActivity中启动了FlutterActivity，并通过指定的引擎ID将其与之关联。

请注意，这只是一个简化的示例，实际集成时可能需要处理更多的细节，比如处理插件注册、处理Activity的生命周期等。