Java android RecyclerView选择: IllegalStateException

Question

我正在创建一个可选择的回收站 View 。我实现了它工作所需的所有类并且它确实工作，我可以选择和取消选择项目并且它们会改变状态。但是，如果我取消选择所有项目然后再次开始选择，应用程序就会崩溃。我没有设法找到任何解决方案，所以这是我的代码:

public class WordsListAdapter extends RecyclerView.Adapter<WordsListAdapter.WordViewHolder> {

private ArrayList<Word> mWordsList = new ArrayList<>();
private SelectionTracker<Word> mSelectionTracker;
private Context mContext;

@Override
public long getItemId(int position) {
    return (long)position;
}

public WordsListAdapter(Context context) {
    mContext = context;
    setHasStableIds(true);
}

void addData(ArrayList<Word> data) {
    mWordsList.addAll(data);
}

void setSelectionTracker(SelectionTracker st) {
    mSelectionTracker = st;
}

@NonNull
@Override
public WordViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
    View v = LayoutInflater.from(viewGroup.getContext())
            .inflate(R.layout.word_list_item, viewGroup, false);

    return new WordViewHolder(v);
}

@Override
public void onBindViewHolder(@NonNull WordViewHolder wordViewHolder, int i) {}

@Override
public void onBindViewHolder(@NonNull WordViewHolder holder, int position, @NonNull List<Object> payloads) {
    Word word = mWordsList.get(position);

    holder.setActivatedState(mSelectionTracker.isSelected(word));
    if(!payloads.contains(SelectionTracker.SELECTION_CHANGED_MARKER)) {
        holder.setData(word);
    }
}

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

public class WordViewHolder extends RecyclerView.ViewHolder implements ViewHolderWithDetails<Long> {

    private View mRootView;
    private TextView mWordTextView, mTranslationTextView;

    WordViewHolder(@NonNull View itemView) {
        super(itemView);

        mRootView = itemView;
        mWordTextView = itemView.findViewById(R.id.wordTextView);
        mTranslationTextView = itemView.findViewById(R.id.translationTextView);
        mWordTextView.setMovementMethod(new ScrollingMovementMethod());
        mTranslationTextView.setMovementMethod(new ScrollingMovementMethod());
    }

    protected void setData(Word word) {
        mWordTextView.setText(word.getWord());
        mTranslationTextView.setText(word.getTranslation());
    }

    public void setActivatedState(boolean state) {
        if(mRootView != null) {
            mRootView.setActivated(state);
            mRootView.setBackgroundColor(mContext.getResources().getColor(state ? R.color.colorPrimaryDark : R.color.colorAccent));
        }
    }


    @Override
    public WordDetails getItemDetails() {
        int pos = getAdapterPosition();
        return new WordDetails(pos, getItemId());
    }
}

public interface ViewHolderWithDetails<TItem> {
    ItemDetailsLookup.ItemDetails<TItem> getItemDetails();
}

public class WordKeyProvider extends ItemKeyProvider<Long> {
    private RecyclerView mRecyclerView;

    protected WordKeyProvider(RecyclerView recyclerView) {
        super(ItemKeyProvider.SCOPE_CACHED);
        mRecyclerView = recyclerView;
    }

    @Nullable
    @Override
    public Long getKey(int position) {
        return getItemId(position);
    }

    @Override
    public int getPosition(@NonNull Long key) {
        RecyclerView.ViewHolder vh = mRecyclerView.findViewHolderForItemId(key);
        return vh == null ? RecyclerView.NO_POSITION : vh.getLayoutPosition();
    }
}


}

WordDetails 类:

public class WordDetails extends ItemDetailsLookup.ItemDetails<Long> {

private int adapterPosition;
private Long selectedKey;

public WordDetails(int position, Long key) {
    adapterPosition = position;
    selectedKey = key;
}

@Override
public int getPosition() {
    return adapterPosition;
}

@Nullable
@Override
public Long getSelectionKey() {
    return selectedKey;
}
}

WordLookup:

public class WordLookup extends ItemDetailsLookup<Long> {

private RecyclerView mRecyclerView;

public WordLookup(RecyclerView recyclerView) {
    mRecyclerView = recyclerView;
}

@Nullable
@Override
public ItemDetails<Long> getItemDetails(@NonNull MotionEvent e) {
    View v = mRecyclerView.findChildViewUnder(e.getX(), e.getY());
    if(v != null) {
        RecyclerView.ViewHolder vh = mRecyclerView.getChildViewHolder(v);
        if(vh instanceof  WordsListAdapter.WordViewHolder) {
            return ((WordsListAdapter.WordViewHolder)vh).getItemDetails();
        }
    }

    return null;
}
}

这就是我初始化 SelectionTracker 的方式:

final SelectionTracker<Long> selectionTracker = new SelectionTracker.Builder<>(
            "my-word-selection",
            mWordsRecyclerView,
            new StableIdKeyProvider(mWordsRecyclerView),
            new WordLookup(mWordsRecyclerView),
            StorageStrategy.createLongStorage()
    ).build();
    mWordsAdapter.setSelectionTracker(selectionTracker);

这是日志:

02-06 17:07:32.302 32103-32103/com.xel E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.xel, PID: 32103
java.lang.IllegalStateException
    at android.support.v4.util.Preconditions.checkState(Preconditions.java:131)
    at android.support.v4.util.Preconditions.checkState(Preconditions.java:143)
    at androidx.recyclerview.selection.GestureSelectionHelper.start(GestureSelectionHelper.java:76)
    at androidx.recyclerview.selection.SelectionTracker$Builder$4.run(SelectionTracker.java:742)
    at androidx.recyclerview.selection.TouchInputHandler.onLongPress(TouchInputHandler.java:136)
    at androidx.recyclerview.selection.GestureRouter.onLongPress(GestureRouter.java:95)
    at android.view.GestureDetector.dispatchLongPress(GestureDetector.java:770)
    at android.view.GestureDetector.access$200(GestureDetector.java:40)
    at android.view.GestureDetector$GestureHandler.handleMessage(GestureDetector.java:293)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:157)
    at android.app.ActivityThread.main(ActivityThread.java:5601)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:774)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:652)

所以我不知道是什么导致了这个错误，可能是什么原因？

Answer 1

确保 build.gradle 文件中的 recyclerview 和 recyclerview-selection 依赖项具有相同的版本，如下所示:

implementation "androidx.recyclerview:recyclerview:1.0.0"
implementation 'androidx.recyclerview:recyclerview-selection:1.0.0'

当我触摸 RecyclerView Items 时，我遇到了 Illegalexception，因为我的 gradle 依赖项是这样的:

implementation "androidx.recyclerview:recyclerview:1.1.0-alpha04"
implementation 'androidx.recyclerview:recyclerview-selection:1.0.0-alpha3'