为什么这些随机标记出现在每个 recyclerview 和 viewpager 项目中？

Question

我在片段中有 2 个回收站视图和一个视图寻呼机。其他一切正常，但两个回收站视图项目都在每个项目的左上角显示一个随机标记。查看寻呼机项目也发生了同样的事情。

此片段在片段 activity 中，并且查看寻呼机正在使用寻呼机适配器。我正在使用 Picasso 库在项目上加载图像，并使用网络策略将图像缓存在磁盘中。

recycler view items appearing like this

view pager items appearing like this

回收器视图适配器

public class CourseListAdapter extends RecyclerView.Adapter<CourseListAdapter.CourseListViewHolder> {

    public static final int HOME_PAGE = 1;
    public static final int DISPLAY_COURSE = 2;

    private Picasso mPicasso;

    private List<DisplayCourse> courseList;

    private static final String TAG = "CourseListAdapter";

    private OnItemClickListener mListener;

    public interface OnItemClickListener {
        void onItemClick(int position, View view);
    }

    private String mSender;

    public void setOnItemClickListener(OnItemClickListener listener) {
        mListener = listener;
    }

    public CourseListAdapter(List<DisplayCourse> courseList, String sender) {
        this.courseList = courseList;
        this.mSender = sender;
        mPicasso = Picasso.get();
    }

    @NonNull
    @Override
    public CourseListViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        LayoutInflater inflater = LayoutInflater.from(parent.getContext());

        switch (viewType) {
            case 1:
                View view1 = inflater.inflate(R.layout.recom_course_home_layout, parent, false);
                return new CourseListViewHolder(view1, mListener);
            case 2:
                View view2 = inflater.inflate(R.layout.display_course_layout, parent, false);
                return new CourseListViewHolder(view2, mListener);

            default:
                View view3 = inflater.inflate(R.layout.section_video_item_layout, parent, false);
                return new CourseListViewHolder(view3, mListener);
        }
    }

    @Override
    public void onBindViewHolder(@NonNull CourseListViewHolder holder, int position) {

        holder.title.setText(courseList.get(position).getCourseTitle());

        mPicasso.load(courseList.get(position).getThumbnailURL())
                .networkPolicy(NetworkPolicy.OFFLINE)
                .into(holder.thumbnail, new Callback() {
                    @Override
                    public void onSuccess() {

                    }

                    @Override
                    public void onError(Exception e) {
                        mPicasso.load(courseList.get(position).getThumbnailURL())
                                .error(R.drawable.ofklogo)
                                .into(holder.thumbnail, new Callback() {
                                    @Override
                                    public void onSuccess() {

                                    }

                                    @Override
                                    public void onError(Exception e) {

                                    }
                                });
                    }
                });
    }

    @Override
    public int getItemCount() {
        return courseList.size();
    }

    public static class CourseListViewHolder extends RecyclerView.ViewHolder {

        ImageView thumbnail;
        TextView title;

        public CourseListViewHolder(@NonNull View itemView, final OnItemClickListener listener) {
            super(itemView);

            title = itemView.findViewById(R.id.courseTitle);
            thumbnail = itemView.findViewById(R.id.courseThumbNailImageView);

            itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    int position = getAdapterPosition();

                    if (listener != null) {
                        if (position != RecyclerView.NO_POSITION) {
                            listener.onItemClick(position, view);
                        }
                    }
                }
            });
        }
    }

    @Override
    public int getItemViewType(int position) {
        if (mSender.equals("home_page")) {
            return HOME_PAGE;
        } else if (mSender.equals("displayCourse")) {
            return DISPLAY_COURSE;
        }
        return -1;
    }
}

查看寻呼机适配器

public class VideoSliderAdapter extends PagerAdapter {

    private boolean doNotifyDataSetChangedOnce = false;

    private static final String TAG = "VideoSliderAdapter";

    private YouTubePlayerView youTubePlayerView;
    private View gradientView;
    private ImageView thumbNail;
    private LinearLayout layout;

    private Picasso picasso;

    private List<Video> videoList;
    private Context mContext;

    private Lifecycle mLifeCycle;

    public VideoSliderAdapter(List<Video> videoList, Context context, Lifecycle lifecycle) {
        this.videoList = videoList;
        this.mContext = context;
        this.mLifeCycle = lifecycle;
        doNotifyDataSetChangedOnce = true;
        picasso = Picasso.get();
    }

    @Override
    public int getCount() {

        if (doNotifyDataSetChangedOnce) {
            doNotifyDataSetChangedOnce = false;
            notifyDataSetChanged();
        }

        return videoList.size();
    }

    @Override
    public int getItemPosition(@NonNull Object object) {
        return POSITION_NONE;
    }

    @Override
    public boolean isViewFromObject(@NonNull View view, @NonNull Object object) {
        return (view == (CardView) object);
    }

    @NonNull
    @Override
    public Object instantiateItem(@NonNull ViewGroup container, int position) {

        LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        View view = inflater.inflate(R.layout.video_paly_layout, container, false);

        TextView title = view.findViewById(R.id.videoTitle);
        title.setText(videoList.get(position).getVideoTitle());

        gradientView = view.findViewById(R.id.gradientView);

        thumbNail = view.findViewById(R.id.videoThumbNail);

        picasso.load(videoList.get(position).getVideoThumbNail())
                .networkPolicy(NetworkPolicy.OFFLINE)
                .into(thumbNail, new Callback() {
                    @Override
                    public void onSuccess() {

                    }

                    @Override
                    public void onError(Exception e) {
                        picasso.load(videoList.get(position).getVideoThumbNail())
                                .error(R.drawable.ofklogo)
                                .into(thumbNail, new Callback() {
                                    @Override
                                    public void onSuccess() {

                                    }

                                    @Override
                                    public void onError(Exception e) {

                                    }
                                });
                    }
                });

        layout = view.findViewById(R.id.videoPlayLayout);

        youTubePlayerView = view.findViewById(R.id.youtube_player_view);

        mLifeCycle.addObserver(youTubePlayerView);

        new AddListener(youTubePlayerView, position).execute();

        container.addView(view);

        return view;

    }

    @Override
    public void destroyItem(@NonNull ViewGroup container, int position, @NonNull Object object) {
        container.removeView((CardView) object);
    }

Recycler view holder 布局

<?xml version="1.0" encoding="utf-8"?>
<androidx.cardview.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="150dp"
    android:layout_height="200dp"
    android:layout_marginStart="8dp"
    android:layout_marginEnd="8dp"
    android:layout_marginBottom="8dp"
    android:clickable="true"
    android:focusable="true"
    android:foreground="?android:attr/selectableItemBackground"
    app:cardCornerRadius="8dp">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <ImageView
            android:id="@+id/courseThumbNailImageView"
            android:layout_width="match_parent"
            android:layout_height="130dp"
            android:layout_alignParentTop="true"
            android:scaleType="fitXY"
            android:src="@drawable/art_thumb" />

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_below="@id/courseThumbNailImageView">

            <TextView
                android:id="@+id/courseTitle"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_centerInParent="true"
                android:maxLines="2"
                android:text="Course title"
                android:textAlignment="center"
                android:textColor="@android:color/black"
                android:textStyle="bold" />

        </RelativeLayout>

    </RelativeLayout>

</androidx.cardview.widget.CardView>

查看寻呼机布局

<?xml version="1.0" encoding="utf-8"?>
<androidx.cardview.widget.CardView 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="200dp"
    app:cardCornerRadius="8dp">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <com.pierfrancescosoffritti.androidyoutubeplayer.core.player.views.YouTubePlayerView
            android:id="@+id/youtube_player_view"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:autoPlay="false" />

        <ImageView
            android:id="@+id/videoThumbNail"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:scaleType="fitXY" />

        <View
            android:id="@+id/gradientView"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="@drawable/gradient_drawable" />

        <LinearLayout
            android:id="@+id/videoPlayLayout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:background="?attr/selectableItemBackground"
            android:clickable="true"
            android:focusable="true"
            android:gravity="center_vertical"
            android:orientation="horizontal"
            android:padding="16dp">

            <ImageView
                android:layout_width="48dp"
                android:layout_height="48dp"
                android:padding="8dp"
                android:src="@drawable/play_button" />

            <TextView
                android:id="@+id/videoTitle"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:ellipsize="end"
                android:maxLines="2"
                android:text="Course title"
                android:textColor="@android:color/white"
                android:textStyle="bold" />


        </LinearLayout>

    </RelativeLayout>

</androidx.cardview.widget.CardView>

Answer 1

使用 Picasso 加载图像时使用：setIndicatorsEnabled(false)

picasso.load(videoList.get(position).getVideoThumbNail())
     .networkPolicy(NetworkPolicy.OFFLINE)
     .setIndicatorsEnabled(false)
     .into(...);

颜色表明：

绿色：图像从内存中获取
蓝色：图像是从磁盘中获取的
红色：图片来自网络

为什么这些随机标记出现在每个 recyclerview 和 viewpager 项目中？

Why these random marks are appearing in every recyclerview and viewpager items?

android

android-recyclerview

android-viewpager