android - 潜在的 Glide 错误 - 在 Android TV 上使用 Dpad 快速滚动时，RecyclerView 项目失去焦点

Question

我正在尝试为 Android TV 制作一个基本的相册应用程序。

使用带有 Glide 的 recyclerview。

问题 :
当通过按下 dpad 向下按钮缓慢滚动时，recyclerview 项目会如预期准确地获得焦点。但是，当按住 dpad 向下按钮时，在快速滚动期间，recyclerview 项目很容易失去焦点，并且焦点会移动到 recyclerview 之外的任何可聚焦 View (在本例中为编辑文本)，并且在手动将焦点移动到 recyclerview 内之前无法滚动再次。

尝试的补救措施 :
1.如果我完全禁用Glide的图像加载(在onBindViewHolder()内部)，焦点永远不会丢失，无论滚动速度有多快，它总是按预期工作。此补救措施没有用，因为需要查看图像。
2. 如果快速滚动受到覆盖 Activity.onKeyDown 方法的限制，以忽略所有键输入，除非自上次 keydown 以来已过去 300 毫秒。同样，这感觉非常hacky，并且完全禁用快速滚动是绝对要求。

请注意，我已经阅读了有关 stackoverflow 的相关 QA。这表明这是 Android 支持库 LayoutManager 代码中的一个错误，这里不是这种情况，因为没有 Glide 它可以正常工作。

如何重现 :创建一个像 ListFragment 这样的 fragment (下面的代码)，然后按住 Down Dpad 按钮尝试快速滚动，您会看到 editText 不断获得焦点。

代码:
ListFragment.java

import android.content.Context;
import android.net.Uri;
import android.os.Bundle;
import android.os.Handler;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v4.view.ViewCompat;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

import com.bumptech.glide.Glide;
import com.bumptech.glide.RequestManager;
import com.bumptech.glide.request.RequestOptions;

import java.util.Random;


public class ListFragment extends Fragment {

    RequestManager glide;

    public ListFragment() {
        // Required empty public constructor
    }

    private RecyclerView recyclerView;
    private RecyclerView.Adapter mAdapter;
    private RecyclerView.LayoutManager layoutManager;

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

    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_list, container, false);
    }

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);

        recyclerView = getActivity().findViewById(R.id.my_recycler_view);
        glide = Glide.with(this);


        layoutManager = new GridLayoutManager(getActivity(),8);
        mAdapter = new MyAdapter();

        recyclerView.setHasFixedSize(true);
        recyclerView.setLayoutManager(layoutManager);
        recyclerView.setAdapter(mAdapter);
    }







    public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {


        private final String[] imageUrls = {"https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/5c2baa1821c67c1430401c65/1546365481213/20181208_0034pp2+810b2.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/5c2baa218a922d1c5eb370c5/1546365483758/20181208_0115pp+810b.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/5c2ba92340ec9ab2ea3f0f73/1546365229886/20181215_0135pp+810b.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/5c2ba8880e2e72e38d92a482/1546365075745/20180914_0189+810b.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/5c2ba885f950b760dd6800a7/1546365086762/20180914_0168pp+810.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/5c2ba9b1032be425c6948ca2/1546365375849/20180818_0014pp+810b.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/5c2baa184ae2379d323c4187/1546365481929/20181208_0065pp+810b2.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/57a256b9e4fcb574ae612941/1470258368357/20160801_0045.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/57a255d1e4fcb574ae61196f/1470256635728/20160717_0391.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/57a25695e4fcb574ae61273c/1470258368265/20160801_0040.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/57a256dbe4fcb574ae612b71/1470258369606/20160801_0108+pp+810+bw.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/57a257088419c29f345a7500/1470258369115/20160801_0108+pp+810.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/5c2ba8e4f950b760dd6804fe/1546365168544/20181101_0067pp+810b.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/5c2ba83270a6adae0b3b6395/1546364992480/20181205_0164pp+810.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/5c2ba8e4575d1f0c318f3727/1546365171139/20181101_0050pp+810b.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/57a2543dd1758e06589e07f1/1470256544677/20160402_0075+810b.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/57a253fad1758e06589e040f/1470256190368/20160402_0039+810b.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/57a255fae4fcb574ae611e08/1470258367476/20160717_0444b.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/57a2573be4fcb574ae613197/1470258370169/20160801_0123+810.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/57a257708419c29f345a7ba7/1470258369404/20160801_0272+810.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/57a25db19f74561d105005de/1470258684806/20160402_0046+810+nik2.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/55076c74e4b07b36ea118be0/1470413754677/20141222_0049.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/57a256688419c29f345a6b17/1470258368620/20160721_0097+pp2.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/57a255c9d1758e06589e1f5e/1470258367695/20160721_0012+ppb.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/56c21ac72b8dde5db5879498/1546363401197/20151107_0094+pp+57c.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/56c20eb662cd945cd5b485f5/1546363401197/20151024_1026+pp+810c.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/53558987e4b007661e339aa7/1470413754809/20140419_0430_pp1+5x7b.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/585db7f3893fc0e1cdfe1bbb/1482536961660/20160507_0069b+810.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/585db8019de4bb91b69d5e37/1482537012182/20160904_0012+810.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/585db8346a496340ce2b8f6e/1482537056393/20160904_0043+pp+810l.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/585db846d482e9c87e69aa3c/1482537056630/20160904_0071+pp+810b.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7dbd4f2a/585db860d2b857ddbd63c824/1482537071373/20160904_0119+pp+810b.jpg","https://static1.squarespace.com/static/51d6d61de4b03f5ac28c861a/55076abee4b038dc7db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        private final RequestOptions options = new RequestOptions().centerCrop();
        private final Random random = new Random();
        private final Handler handler = new Handler();

        public class ViewHolder extends RecyclerView.ViewHolder {
            public ImageView icon;
            public View layout;

            ViewHolder(View v) {
                super(v);
                layout = v;
                icon =  v.findViewById(R.id.icon);
            }
        }


        @Override
        public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
                                                       int viewType) {

            LayoutInflater inflater = LayoutInflater.from(
                    parent.getContext());

            View v =
                    inflater.inflate(R.layout.item_recycler_view, parent, false);

            MyAdapter.ViewHolder vh = new MyAdapter.ViewHolder(v);
            return vh;
        }




        @Override
        public void onBindViewHolder(final MyAdapter.ViewHolder holder, final int position) {

            final String name = imageUrls[random.nextInt(imageUrls.length - 1)];


            //Commenting this out resolves focus loss
            glide.load(name).into(holder.icon);
        }

        @Override
        public void onViewRecycled(@NonNull ViewHolder holder) {
            super.onViewRecycled(holder);
            glide.clear(holder.icon);
        }

        // Return the size of your dataset (invoked by the layout manager)
        @Override
        public int getItemCount() {
            return Integer.MAX_VALUE;
        }

    }
}

布局:
item_recycler_view.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"
    android:layout_height="wrap_content"

    android:foreground="@drawable/fg_selectable"

    android:clickable="true"
    android:focusable="true"
    android:focusableInTouchMode="false"
    android:descendantFocusability="blocksDescendants"

    android:layout_margin="2dp"
    >

    <ImageView
        android:id="@+id/icon"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        app:layout_constraintDimensionRatio="27:41"

        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"

        android:background="@color/colorPrimaryDark"

        tools:src="@tools:sample/avatars"
         />

</android.support.constraint.ConstraintLayout>

fragment 列表.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    tools:context=".ListFragment"
    android:orientation="horizontal"
    >

    <EditText
        android:id="@+id/editText"
        android:text="test"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:nextFocusDown="@id/editText"
        />

    <android.support.v7.widget.RecyclerView
        android:id="@+id/my_recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        />

</LinearLayout>

Answer 1

为什么在 onViewRecycled 中需要 glide.clear()？我的猜测是，它与快速滚动期间频繁的 Glide 加载和清除有关。 Glide 可能会有些困惑。另外，为什么不 Leanback Library 和 GridFragment？根据我的经验，它适用于 Glide 和快速滚动。