向 Android 应用添加 Flutter Fragment

public class MyActivity extends FragmentActivity {
    // 定义一个 tag 字符串，用于在该 Activity 的 FragmentManager 中表示 FlutterFragment。此值可以是您想要的任何值。
    private static final String TAG_FLUTTER_FRAGMENT = "flutter_fragment";

    // 声明一个局部变量来引用 FlutterFragment，以便您可以稍后向其转发调用。
    private FlutterFragment flutterFragment;

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

        // 加载一个包含 FlutterFragment 容器的布局。对于此示例，假设存在一个 ID 为 R.id.fragment_container 的 FrameLayout。
        setContentView(R.layout.my_activity_layout);

        // 获取对 Activity 的 FragmentManager 的引用，以添加新的 FlutterFragment 或查找现有的 FlutterFragment。
        FragmentManager fragmentManager = getSupportFragmentManager();

        // 尝试查找现有的 FlutterFragment，以防这不是 onCreate() 第一次运行。
        flutterFragment = (FlutterFragment) fragmentManager
            .findFragmentByTag(TAG_FLUTTER_FRAGMENT);

        // 如果不存在 FlutterFragment，则创建并附加一个。
        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);
    }
}

// 在您的应用程序中的某个地方，在需要 FlutterFragment 之前，例如在 Application 类中...
// 实例化一个 FlutterEngine。
FlutterEngine flutterEngine = new FlutterEngine(context);

// 开始在 FlutterEngine 中执行 Dart 代码。
flutterEngine.getDartExecutor().executeDartEntrypoint(
    DartEntrypoint.createDefault()
);

// 缓存预热的 FlutterEngine，以便稍后由 FlutterFragment 使用。
FlutterEngineCache
  .getInstance()
  .put("my_engine_id", flutterEngine);

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

public class MyApplication extends Application {
  @Override
  public void onCreate() {
    super.onCreate();
    // 实例化一个 FlutterEngine。
    flutterEngine = new FlutterEngine(this);
    // 配置初始路由。
    flutterEngine.getNavigationChannel().setInitialRoute("your/route/here");
    // 开始执行 Dart 代码以预热 FlutterEngine。
    flutterEngine.getDartExecutor().executeDartEntrypoint(
      DartEntrypoint.createDefault()
    );
    // 缓存 FlutterEngine 以供 FlutterActivity 或 FlutterFragment 使用。
    FlutterEngineCache
      .getInstance()
      .put("my_engine_id", flutterEngine);
  }
}

// 使用新的 FlutterEngine。
FlutterFragment flutterFragment = FlutterFragment.withNewEngine()
    .initialRoute("myInitialRoute/")
    .build();

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

// 使用新的 FlutterEngine。
FlutterFragment flutterFragment = FlutterFragment.withNewEngine()
    .renderMode(FlutterView.RenderMode.texture)
    .build();

// 使用缓存的 FlutterEngine。
FlutterFragment flutterFragment = FlutterFragment.withCachedEngine("my_engine_id")
    .renderMode(FlutterView.RenderMode.texture)
    .build();

// 使用新的 FlutterEngine。
FlutterFragment flutterFragment = FlutterFragment.withNewEngine()
    .transparencyMode(FlutterView.TransparencyMode.transparent)
    .build();

// 使用缓存的 FlutterEngine。
FlutterFragment flutterFragment = FlutterFragment.withCachedEngine("my_engine_id")
    .transparencyMode(FlutterView.TransparencyMode.transparent)
    .build();

// 使用新的 FlutterEngine。
FlutterFragment flutterFragment = FlutterFragment.withNewEngine()
    .shouldAttachEngineToActivity(false)
    .build();

// 使用缓存的 FlutterEngine。
FlutterFragment flutterFragment = FlutterFragment.withCachedEngine("my_engine_id")
    .shouldAttachEngineToActivity(false)
    .build();