将 Flutter Fragment 添加到 Android 应用

public class MyActivity extends FragmentActivity {
    // Define a tag String to represent the FlutterFragment within this
    // Activity's FragmentManager. This value can be whatever you'd like.
    private static final String TAG_FLUTTER_FRAGMENT = "flutter_fragment";

    // Declare a local variable to reference the FlutterFragment so that you
    // can forward calls to it later.
    private FlutterFragment flutterFragment;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Inflate a layout that has a container for your FlutterFragment.
        // For this example, assume that a FrameLayout exists with an ID of
        // R.id.fragment_container.
        setContentView(R.layout.my_activity_layout);

        // Get a reference to the Activity's FragmentManager to add a new
        // FlutterFragment, or find an existing one.
        FragmentManager fragmentManager = getSupportFragmentManager();

        // Attempt to find an existing FlutterFragment,
        // in case this is not the first time that onCreate() was run.
        flutterFragment = (FlutterFragment) fragmentManager
            .findFragmentByTag(TAG_FLUTTER_FRAGMENT);

        // Create and attach a FlutterFragment if one does not exist.
        if (flutterFragment == null) {
            flutterFragment = FlutterFragment.createDefault();

            fragmentManager
                .beginTransaction()
                .add(
                    R.id.fragment_container,
                    flutterFragment,
                    TAG_FLUTTER_FRAGMENT
                )
                .commit();
        }
    }
}

public class MyActivity extends FragmentActivity {
    @Override
    public void onPostResume() {
        super.onPostResume();
        flutterFragment.onPostResume();
    }

    @Override
    protected void onNewIntent(@NonNull Intent intent) {
        flutterFragment.onNewIntent(intent);
    }

    @Override
    public void onBackPressed() {
        flutterFragment.onBackPressed();
    }

    @Override
    public void onRequestPermissionsResult(
        int requestCode,
        @NonNull String[] permissions,
        @NonNull int[] grantResults
    ) {
        flutterFragment.onRequestPermissionsResult(
            requestCode,
            permissions,
            grantResults
        );
    }

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

    @Override
    public void onUserLeaveHint() {
        flutterFragment.onUserLeaveHint();
    }

    @Override
    public void onTrimMemory(int level) {
        super.onTrimMemory(level);
        flutterFragment.onTrimMemory(level);
    }
}

// Somewhere in your app, before your FlutterFragment is needed,
// like in the Application class ...
// Instantiate a FlutterEngine.
FlutterEngine flutterEngine = new FlutterEngine(context);

// Start executing Dart code in the FlutterEngine.
flutterEngine.getDartExecutor().executeDartEntrypoint(
    DartEntrypoint.createDefault()
);

// Cache the pre-warmed FlutterEngine to be used later by FlutterFragment.
FlutterEngineCache
  .getInstance()
  .put("my_engine_id", flutterEngine);

FlutterFragment.withCachedEngine("my_engine_id").build();

public class MyApplication extends Application {
  @Override
  public void onCreate() {
    super.onCreate();
    // Instantiate a FlutterEngine.
    flutterEngine = new FlutterEngine(this);
    // Configure an initial route.
    flutterEngine.getNavigationChannel().setInitialRoute("your/route/here");
    // Start executing Dart code to pre-warm the FlutterEngine.
    flutterEngine.getDartExecutor().executeDartEntrypoint(
      DartEntrypoint.createDefault()
    );
    // Cache the FlutterEngine to be used by FlutterActivity or FlutterFragment.
    FlutterEngineCache
      .getInstance()
      .put("my_engine_id", flutterEngine);
  }
}

// With a new FlutterEngine.
FlutterFragment flutterFragment = FlutterFragment.withNewEngine()
    .initialRoute("myInitialRoute/")
    .build();

FlutterFragment flutterFragment = FlutterFragment.withNewEngine()
    .dartEntrypoint("mySpecialEntrypoint")
    .build();

// With a new FlutterEngine.
FlutterFragment flutterFragment = FlutterFragment.withNewEngine()
    .renderMode(FlutterView.RenderMode.texture)
    .build();

// With a cached FlutterEngine.
FlutterFragment flutterFragment = FlutterFragment.withCachedEngine("my_engine_id")
    .renderMode(FlutterView.RenderMode.texture)
    .build();

// Using a new FlutterEngine.
FlutterFragment flutterFragment = FlutterFragment.withNewEngine()
    .transparencyMode(FlutterView.TransparencyMode.transparent)
    .build();

// Using a cached FlutterEngine.
FlutterFragment flutterFragment = FlutterFragment.withCachedEngine("my_engine_id")
    .transparencyMode(FlutterView.TransparencyMode.transparent)
    .build();

// Using a new FlutterEngine.
FlutterFragment flutterFragment = FlutterFragment.withNewEngine()
    .shouldAttachEngineToActivity(false)
    .build();

// Using a cached FlutterEngine.
FlutterFragment flutterFragment = FlutterFragment.withCachedEngine("my_engine_id")
    .shouldAttachEngineToActivity(false)
    .build();