java - 仅当不直接扩展 RecyclerView 时才会出现 InflateException

Question

我之前遇到过 InflateException，“二进制 XML 文件中的类膨胀错误”，这通常是由于属性写入错误或加载大图像时出现内存不足错误。但是，我不认为这是这种情况下的错误，因为我没有更改加载的任何属性或图像。我正在使用 Google 的 Blockly 库，并且在 xml 中加载 Blockly 的默认类时效果很好:

<com.google.blockly.android.ui.CategoryTabs
    android:id="@+id/category_tabs"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" />

但是，当我尝试加载扩展 CategoryTabs 的修改类时，我在第 37 行收到 InflateException，其中 37 是 ModifiedCategoryTabs 的开始标记:

<com.example.travisho.blockly.ModifiedCategoryTabs
    android:id="@+id/category_tabs"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" />

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.travisho.blockly/com.example.travisho.blockly.BlocklyActivity}: android.view.InflateException: Binary XML file line #37: Error inflating class com.example.travisho.blockly.ModifiedCategoryTabs
                                                                              at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2366)

然后我的 ModifiedCategoryTabs 类很简单:

public class ModifiedCategoryTabs extends CategoryTabs{

    public ModifiedCategoryTabs(Context context) {
        super(context);
    }
}

Blockly 中的 CategoryTab 是:

public class CategoryTabs extends RecyclerView {
public static final String TAG = "CategoryTabs";

public static final int HORIZONTAL = OrientationHelper.HORIZONTAL;
public static final int VERTICAL = OrientationHelper.VERTICAL;

private final LinearLayoutManager mLayoutManager;
private final CategoryAdapter mAdapter;
protected final List<BlocklyCategory> mCategories = new ArrayList<>();

protected @Rotation.Enum int mLabelRotation = Rotation.NONE;
protected boolean mTapSelectedDeselects = false;

private LabelAdapter mLabelAdapter;
protected @Nullable CategorySelectorUI.Callback mCallback;
protected @Nullable
BlocklyCategory mCurrentCategory;

public CategoryTabs(Context context) {
    this(context, null, 0);
}

public CategoryTabs(Context context, AttributeSet attrs) {
    this(context, attrs, 0);
}

public CategoryTabs(Context context, AttributeSet attrs, int style) {
    super(context, attrs, style);

    mLayoutManager = new LinearLayoutManager(context);
    setLayoutManager(mLayoutManager);
    mAdapter = new CategoryAdapter();
    setAdapter(mAdapter);
    setLabelAdapter(new DefaultTabsAdapter());

    TypedArray a = context.getTheme().obtainStyledAttributes(
            attrs,
            R.styleable.BlocklyCategory,
            0, 0);
    try {
        //noinspection ResourceType
        mLabelRotation = a.getInt(R.styleable.BlocklyCategory_labelRotation, mLabelRotation);
        int orientation = a.getInt(R.styleable.BlocklyCategory_scrollOrientation, VERTICAL);
        mLayoutManager.setOrientation(orientation);
    } finally {
        a.recycle();
    }
}

/**
 * Sets the {@link Adapter} responsible for the label views.
 */
public void setLabelAdapter(LabelAdapter labelAdapter) {
    mLabelAdapter = labelAdapter;
    mAdapter.notifyDataSetChanged();
}

/**
 * Sets the {@link CategorySelectorUI.Callback} used by this instance.
 *
 * @param callback The {@link CategorySelectorUI.Callback} for event handling.
 */
public void setCallback(@Nullable CategorySelectorUI.Callback callback) {
    mCallback = callback;
}

/**
 * Sets the orientation in which the tabs will accumulate, which is also the scroll direction
 * when there are more tabs than space allows.
 *
 * @param orientation Either {@link #HORIZONTAL} or {@link #VERTICAL}.
 */
public void setOrientation(int orientation) {
    mLayoutManager.setOrientation(orientation);
}

/**
 * Sets the {@link Rotation} direction constant for the tab labels.
 *
 * @param labelRotation The {@link Rotation} direction constant for the tab labels.
 */
public void setLabelRotation(@Rotation.Enum int labelRotation) {
    mLabelRotation = labelRotation;
    mAdapter.notifyDataSetChanged();
}

/**
 * Sets whether the selected tab will deselect when clicked again.
 *
 * @param tapSelectedDeselects If {@code true}, selected tab will deselect when clicked again.
 */
public void setTapSelectedDeselects(boolean tapSelectedDeselects) {
    mTapSelectedDeselects = tapSelectedDeselects;
}

/**
 * Sets the list of {@link BlocklyCategory}s used to populate the tab labels.
 *
 * @param categories The list of {@link BlocklyCategory}s used to populate the tab labels.
 */
public void setCategories(List<BlocklyCategory> categories) {
    mCategories.clear();
    mCategories.addAll(categories);
    mAdapter.notifyDataSetChanged();
}

/**
 * Sets the currently selected tab. If the tab is not a member of the assigned categories, no
 * tab will render selected.
 *
 * @param category
 */
public void setSelectedCategory(@Nullable BlocklyCategory category) {
    if (mCurrentCategory == category) {
        return;
    }
    if (mCurrentCategory != null) {
        // Deselect the old tab.
        TabLabelHolder vh = getTabLabelHolder(mCurrentCategory);
        if (vh != null && mLabelAdapter != null) {  // Tab might not be rendered or visible yet.
            // Update style. Don't use notifyItemChanged(..), due to a resulting UI flash.
            mLabelAdapter.onSelectionChanged(
                    vh.mLabel, vh.mCategory, vh.getAdapterPosition(), false);
        }
    }
    mCurrentCategory = category;
    if (mCurrentCategory != null && mLabelAdapter != null) {
        // Select the new tab.
        TabLabelHolder vh = getTabLabelHolder(mCurrentCategory);
        if (vh != null) {  // Tab might not be rendered or visible yet.
            // Update style. Don't use notifyItemChanged(..), due to a resulting UI flash.
            mLabelAdapter.onSelectionChanged(
                    vh.mLabel, vh.mCategory, vh.getAdapterPosition(), true);
        }
    }
}

/**
 * @return The currently highlighted category or null.
 */
public BlocklyCategory getSelectedCategory() {
    return mCurrentCategory;
}

public int getTabCount() {
    return mCategories.size();
}

private void onCategoryClicked(BlocklyCategory category) {
    if (mCallback != null) {
        mCallback.onCategoryClicked(category);
    }
}

private TabLabelHolder getTabLabelHolder(BlocklyCategory category) {
    int childCount = getChildCount();
    for (int i = 0; i < childCount; ++i) {
        View child = getChildAt(i);
        TabLabelHolder vh = (TabLabelHolder) child.getTag();
        if (vh != null && vh.mCategory == category) {
            return vh;
        }
    }
    return null;
}

private class CategoryAdapter extends RecyclerView.Adapter<TabLabelHolder> {
    @Override
    public int getItemCount() {
        return getTabCount();
    }

    @Override
    public TabLabelHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        if (mLabelAdapter == null) {
            throw new IllegalStateException("No LabelAdapter assigned.");
        }
        return new TabLabelHolder(mLabelAdapter.onCreateLabel());
    }

    @Override
    public void onBindViewHolder(TabLabelHolder holder, int tabPosition) {
        final BlocklyCategory category = mCategories.get(tabPosition);
        boolean isSelected = (category == mCurrentCategory);
        // These may throw a NPE, but that is an illegal state checked above.
        mLabelAdapter.onBindLabel(holder.mLabel, category, tabPosition);
        mLabelAdapter.onSelectionChanged(holder.mLabel, category, tabPosition, isSelected);
        holder.mCategory = category;
        holder.mRotator.setChildRotation(mLabelRotation);
        holder.mRotator.setTag(holder);  // For getTabLabelHolder() and deselection
        holder.mLabel.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View label) {
                onCategoryClicked(category);
            }
        });
    }

    @Override
    public void onViewRecycled(TabLabelHolder holder) {
        holder.mRotator.setTag(null);  // Remove reference to holder.
        holder.mCategory = null;
        holder.mLabel.setOnClickListener(null);
    }
}

/** Manages TextView labels derived from {@link R.layout#default_toolbox_tab}. */
protected class DefaultTabsAdapter extends CategoryTabs.LabelAdapter {
    @Override
    public View onCreateLabel() {
        return (TextView) LayoutInflater.from(getContext())
                .inflate(R.layout.default_toolbox_tab, null);
    }

    /**
     * Assigns the category name to the {@link TextView}. Tabs without labels will be assigned
     * the text {@link R.string#blockly_toolbox_default_category_name} ("Blocks" in English).
     *
     * @param labelView The view used as the label.
     * @param category The {@link BlocklyCategory}.
     * @param position The ordering position of the tab.
     */
    @Override
    public void onBindLabel(View labelView, BlocklyCategory category, int position) {
        String labelText = category.getCategoryName();
        if (TextUtils.isEmpty(labelText)) {
            labelText = getContext().getString(R.string.blockly_toolbox_default_category_name);
        }
        ((TextView) labelView).setText(labelText);
    }

}

public abstract static class LabelAdapter {
    /**
     * Create a label view for a tab. This view will later be assigned an
     * {@link View.OnClickListener} to handle tab selection and deselection.
     */
    public abstract View onCreateLabel();

    /**
     * Bind a {@link BlocklyCategory} to a label view, with any appropriate styling.
     *
     * @param labelView The tab's label view.
     * @param category The category to bind to.
     * @param position The position of the category in the list of tabs.
     */
    public abstract void onBindLabel(View labelView, BlocklyCategory category, int position);

    /**
     * Called when a label is bound or when clicking results in a selection change. Responsible
     * for updating the view to reflect the new state, including applying the category name.
     * <p/>
     * By default, it calls {@link View#setSelected(boolean)}. Many views and/or styles will
     * handle this appropriately.
     *
     * @param labelView The tab's label view.
     * @param category The category to bind to.
     * @param position The position of the category in the list of tabs.
     * @param isSelected the new selection state.
     */
    public void onSelectionChanged(
            View labelView, BlocklyCategory category, int position, boolean isSelected) {
        labelView.setSelected(isSelected);
    }
}

/**
 * ViewHolder for the display name of a category in the toolbox.
 */
private static class TabLabelHolder extends RecyclerView.ViewHolder {
    public final RotatedViewGroup mRotator;
    public final View mLabel;

    public BlocklyCategory mCategory;

    TabLabelHolder(View label) {
        super(new RotatedViewGroup(label.getContext()));
        mRotator = (RotatedViewGroup) itemView;
        mLabel = label;
        mRotator.addView(mLabel);
    }
}}

请记住，它在膨胀 CategoryTabs 时有效，但在膨胀 ModifiedCategoryTabs 时无效，是否可能是由于 ModifiedCategoryTabs 没有直接子类化 RecyclerView？我认为在这两种情况下，通货膨胀都应该起作用，因为 ModifiedCategoryTabs 是 CategoryTabs 的子类，其中 ModifiedCategoryTabs 不会覆盖 CategoryTabs 中的任何内容。

Answer 1

And then my ModifiedCategoryTabs class is simply:

您需要添加两个参数构造函数 (ModifiedCategoryTabs(Context context, AttributeSet attrs))，因为布局充气器使用的是该构造函数。