activity 最小化后再恢复后视图再次可见

Question

我的应用程序中出现了这个奇怪的东西。

我有一个AppCompatActivity，里面有ViewPager，里面有两个片段。我在两个片段中都添加了 LottieAnimationView。

在 FragmentA 中，我使用 Retrofit 从服务器获取数据，在加载时，它隐藏了 LottieAnimationView。在 FragmentB 中（仅用于检查错误），我只是使用 Handler 在 3 秒后隐藏 LottieAnimationView。

现在，每当我最小化应用程序，然后再次打开它时，我只在 FragmentA 中看到 setVisibility(View.GONE) 的 LottieAnimationView。在 FragmentB 中，当我 setVisibility(View.GONE) 最小化并再次打开应用程序（按预期工作）后，我没有看到视图。

这是我在 FragmentA 中看到的图像。

LottieAnimationView 处于暂停状态。

这是我的 FragmentA.

的代码

public class FragmentA extends Fragment {

    private AdapterEventStore mAdapter;
    private List<Item> mStore;
    private final String hostName = "https://xxx.xxx.xxx";
    private View view;
    private Context context;
    private LottieAnimationView lottieAnimationView;

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        view = inflater.inflate(R.layout.fragment_a, container, false);
        context = view.getContext();
        lottieAnimationView = view.findViewById(R.id.ais_lav_loading);
        lottieAnimationView.setVisibility(View.VISIBLE);
        initRecyclerView();
        return view;
    }


    private void initRecyclerView() {
        RecyclerView store = view.findViewById(R.id.ais_rv_event_store);
        store.setLayoutManager(new StaggeredGridLayoutManager(2, StaggeredGridLayoutManager.VERTICAL));
        mStore = new ArrayList<>();
        mAdapter = new AdapterEventStore(context, mStore);
        store.setAdapter(mAdapter);
        fetchDataFromServer();
    }

    private void fetchDataFromServer() {
        HttpLoggingInterceptor logging = new HttpLoggingInterceptor();
        logging.setLevel(HttpLoggingInterceptor.Level.BODY);
        OkHttpClient.Builder httpClient = new OkHttpClient.Builder();
        httpClient.addInterceptor(logging);

        final Retrofit retrofit = new Retrofit.Builder()
                .client(httpClient.build())
                .addConverterFactory(GsonConverterFactory.create())
                .baseUrl(hostName)
                .build();
        APIGetItem itemShop = retrofit.create(APIGetItem.class);

        Call<ModelEventExclusive> call = itemShop.getEventStore(hostName);
        call.enqueue(new Callback<ModelEventExclusive>() {
            @Override
            public void onResponse(Call<ModelEventExclusive> call, Response<ModelEventExclusive> response) {
                Log.e("Response: ", response.body().getItems().get(0).getItemName());
                mEventStore.addAll(response.body().getItems());
                mAdapter.notifyDataSetChanged();
                hideLottieAnimation();
            }

            @Override
            public void onFailure(Call<ModelEventExclusive> call, Throwable t) {
                hideLottieAnimation();
                Toast.makeText(context, "Error:"+t.getLocalizedMessage(), Toast.LENGTH_SHORT).show();
                Log.e("Error occurred: ", t.getMessage());
            }
        });
    }

    private void hideLottieAnimation(){
        lottieAnimationView.cancelAnimation();
        lottieAnimationView.setVisibility(View.GONE);
    }
}

FragmentA

的布局

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/ais_rv_event_store"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <com.airbnb.lottie.LottieAnimationView
        android:id="@+id/ais_lav_loading"
        android:layout_width="250dp"
        android:layout_height="250dp"
        android:layout_gravity="center"
        app:lottie_autoPlay="true"
        app:lottie_loop="true"
        android:visibility="gone"
        app:lottie_repeatMode="reverse"
        app:lottie_rawRes="@raw/loading" />
</FrameLayout>

请注意，LottieAnimationView 的可见性最初设置为 GONE。上面获取项目的代码 100% 有效，请不要指出 syntax/variable 名称中的任何错误，因为我在试图隐藏实际 variable/class 名称方面做得不好。

这是 FragmentB

的代码

public class FragmentB extends Fragment {
    private LottieAnimationView anim_loading;
    private View view;

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        view = inflater.inflate(R.layout.fragment_b, container, false);
        anim_loading = view.findViewById(R.id.lav_loading);
        final Handler handler = new Handler();
        handler.postDelayed(new Runnable() {
            @Override
            public void run() {
                anim_loading.cancelAnimation();
                anim_loading.setVisibility(View.GONE);
            }
        }, 3000);
        return view;
    }
}

你能告诉我这里做错了什么吗？为什么它在一个片段中按预期工作而在另一个片段中却没有？它与我将其隐藏在 Retrofit 回调中的方式有什么关系吗？

Answer 1

从 conCrete 中删除这一行并将其添加到像这样的从 Server() 方法获取数据中。

    public class FragmentA extends Fragment {

    private AdapterEventStore mAdapter;
    private List<Item> mStore;
    private final String hostName = "https://xxx.xxx.xxx";
    private View view;
    private Context context;
    private LottieAnimationView lottieAnimationView;

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        view = inflater.inflate(R.layout.fragment_a, container, false);
        context = view.getContext();
        lottieAnimationView = view.findViewById(R.id.ais_lav_loading);
        lottieAnimationView.setVisibility(View.VISIBLE);
        initRecyclerView();
        return view;
    }


    private void initRecyclerView() {
        RecyclerView store = view.findViewById(R.id.ais_rv_event_store);
        store.setLayoutManager(new StaggeredGridLayoutManager(2, StaggeredGridLayoutManager.VERTICAL));
        mStore = new ArrayList<>();
        mAdapter = new AdapterEventStore(context, mStore);
        store.setAdapter(mAdapter);
        fetchDataFromServer();
    }

    private void fetchDataFromServer() {
        HttpLoggingInterceptor logging = new HttpLoggingInterceptor();
        logging.setLevel(HttpLoggingInterceptor.Level.BODY);
        OkHttpClient.Builder httpClient = new OkHttpClient.Builder();
        httpClient.addInterceptor(logging);

        final Retrofit retrofit = new Retrofit.Builder()
                .client(httpClient.build())
                .addConverterFactory(GsonConverterFactory.create())
                .baseUrl(hostName)
                .build();
        APIGetItem itemShop = retrofit.create(APIGetItem.class);



        Call<ModelEventExclusive> call = itemShop.getEventStore(hostName);
        call.enqueue(new Callback<ModelEventExclusive>() {
            @Override
            public void onResponse(Call<ModelEventExclusive> call, Response<ModelEventExclusive> response) {
                Log.e("Response: ", response.body().getItems().get(0).getItemName());
                mEventStore.addAll(response.body().getItems());
                mAdapter.notifyDataSetChanged();
                hideLottieAnimation();
            }

            @Override
            public void onFailure(Call<ModelEventExclusive> call, Throwable t) {
                hideLottieAnimation();
                Toast.makeText(context, "Error:"+t.getLocalizedMessage(), Toast.LENGTH_SHORT).show();
                Log.e("Error occurred: ", t.getMessage());
            }
        });
    }

    private void hideLottieAnimation(){
        lottieAnimationView.cancelAnimation();
        lottieAnimationView.setVisibility(View.GONE);
    }
  @Override
    public void onResume() {
        super.onResume();
        lottieAnimationView.setVisibility(View.GONE);
    }
}

Answer 2

问题是，当您从后台获取时，会调用 onResume，因此您需要添加行以隐藏 onResume 中的视图，而不是 onCreateView .

查看 Android Developer page on fragments 了解更多详情。

activity 最小化后再恢复后视图再次可见

View visible again after activity is minimized and then restored

java

android

lottie