java - 在我的应用程序上生成 APK 构造函数问题

Question

我开发了一些应用程序，它运行良好，没有任何问题。调试没有问题。我使用 ShareActionProvider 类方法创建了一些自定义类，用于从 ActionShareProvider 菜单检查用户操作。当我想从 Android Studio 生成 APK 时，它给了我这个错误；

错误:(87) 错误:此类应提供默认构造函数(不带参数的公共(public)构造函数)(com.esmobileinc.vetmapp.ShareActionProvider) [可实例化]

有 ShareActionProvider 类；

public class ShareActionProvider extends ActionProvider {

public void setOnShareListener(OnShareListener listener) {
    mOnShareListener = listener;
    setActivityChooserPolicyIfNeeded();
}

/**
 * Listener for the event of selecting a share target.
 */
public interface OnShareTargetSelectedListener {

    /**
     * Called when a share target has been selected. The client can
     * decide whether to perform some action before the sharing is
     * actually performed.
     * <p>
     * <strong>Note:</strong> Modifying the intent is not permitted and
     *     any changes to the latter will be ignored.
     * </p>
     * <p>
     * <strong>Note:</strong> You should <strong>not</strong> handle the
     *     intent here. This callback aims to notify the client that a
     *     sharing is being performed, so the client can update the UI
     *     if necessary.
     * </p>
     *
     * @param source The source of the notification.
     * @param intent The intent for launching the chosen share target.
     * @return The return result is ignored. Always return false for consistency.
     */
    public boolean onShareTargetSelected(ShareActionProvider source, Intent intent);
}


private OnShareListener mOnShareListener; //also need to add getter and setter

public interface OnShareListener {
    /**
     * Called when a share target has been selected. The client can
     * decide whether to perform some action before the sharing is
     * actually performed OR handle the action itself.



     *
     * @param source The source of the notification.
     * @param intent The intent for launching the chosen share target.
     * @return Return true if you have handled the intent.
     */
    public boolean willHandleShareTarget(ShareActionProvider source, Intent intent);

}

/**
 * The default for the maximal number of activities shown in the sub-menu.
 */
private static final int DEFAULT_INITIAL_ACTIVITY_COUNT = 4;

/**
 * The the maximum number activities shown in the sub-menu.
 */
private int mMaxShownActivityCount = DEFAULT_INITIAL_ACTIVITY_COUNT;

/**
 * Listener for handling menu item clicks.
 */
private final ShareMenuItemOnMenuItemClickListener mOnMenuItemClickListener =
        new ShareMenuItemOnMenuItemClickListener();

/**
 * The default name for storing share history.
 */
public static final String DEFAULT_SHARE_HISTORY_FILE_NAME = "share_history.xml";

/**
 * Context for accessing resources.
 */
private final Context mContext;

/**
 * The name of the file with share history data.
 */
private String mShareHistoryFileName = DEFAULT_SHARE_HISTORY_FILE_NAME;

private OnShareTargetSelectedListener mOnShareTargetSelectedListener;

private OnChooseActivityListener mOnChooseActivityListener;

/**
 * Creates a new instance.
 *
 * @param context Context for accessing resources.
 */
public ShareActionProvider(Context context) {
    super(context);
    mContext = context;
}

/**
 * Sets a listener to be notified when a share target has been selected.
 * The listener can optionally decide to handle the selection and
 * not rely on the default behavior which is to launch the activity.
 * <p>
 * <strong>Note:</strong> If you choose the backing share history file
 *     you will still be notified in this callback.
 * </p>
 * @param listener The listener.
 */
public void setOnShareTargetSelectedListener(OnShareTargetSelectedListener listener) {
    mOnShareTargetSelectedListener = listener;
    setActivityChooserPolicyIfNeeded();
}

/**
 * {@inheritDoc}
 */
@Override
public View onCreateActionView() {
    // Create the view and set its data model.
    ActivityChooserView activityChooserView = new ActivityChooserView(mContext);
    if (!activityChooserView.isInEditMode()) {
        ActivityChooserModel dataModel = ActivityChooserModel.get(mContext, mShareHistoryFileName);
        activityChooserView.setActivityChooserModel(dataModel);
    }

    // Lookup and set the expand action icon.
    TypedValue outTypedValue = new TypedValue();
    mContext.getTheme().resolveAttribute(R.attr.actionModeShareDrawable, outTypedValue, true);
    Drawable drawable = TintManager.getDrawable(mContext, outTypedValue.resourceId);
    activityChooserView.setExpandActivityOverflowButtonDrawable(drawable);
    activityChooserView.setProvider(this);

    // Set content description.
    activityChooserView.setDefaultActionButtonContentDescription(
            R.string.abc_shareactionprovider_share_with_application);
    activityChooserView.setExpandActivityOverflowButtonContentDescription(
            R.string.abc_shareactionprovider_share_with);

    return activityChooserView;
}

/**
 * {@inheritDoc}
 */
@Override
public boolean hasSubMenu() {
    return true;
}

/**
 * {@inheritDoc}
 */
@Override
public void onPrepareSubMenu(SubMenu subMenu) {
    // Clear since the order of items may change.
    subMenu.clear();

    ActivityChooserModel dataModel = ActivityChooserModel.get(mContext, mShareHistoryFileName);
    PackageManager packageManager = mContext.getPackageManager();

    final int expandedActivityCount = dataModel.getActivityCount();
    final int collapsedActivityCount = Math.min(expandedActivityCount, mMaxShownActivityCount);

    // Populate the sub-menu with a sub set of the activities.
    for (int i = 0; i < collapsedActivityCount; i++) {
        ResolveInfo activity = dataModel.getActivity(i);
        subMenu.add(0, i, i, activity.loadLabel(packageManager))
                .setIcon(activity.loadIcon(packageManager))
                .setOnMenuItemClickListener(mOnMenuItemClickListener);
    }

    if (collapsedActivityCount < expandedActivityCount) {
        // Add a sub-menu for showing all activities as a list item.
        SubMenu expandedSubMenu = subMenu.addSubMenu(Menu.NONE, collapsedActivityCount,
                collapsedActivityCount,
                mContext.getString(R.string.abc_activity_chooser_view_see_all));
        for (int i = 0; i < expandedActivityCount; i++) {
            ResolveInfo activity = dataModel.getActivity(i);
            expandedSubMenu.add(0, i, i, activity.loadLabel(packageManager))
                    .setIcon(activity.loadIcon(packageManager))
                    .setOnMenuItemClickListener(mOnMenuItemClickListener);
        }
    }
}

/**
 * Sets the file name of a file for persisting the share history which
 * history will be used for ordering share targets. This file will be used
 * for all view created by {@link #onCreateActionView()}. Defaults to
 * {@link #DEFAULT_SHARE_HISTORY_FILE_NAME}. Set to <code>null</code>
 * if share history should not be persisted between sessions.
 * <p>
 * <strong>Note:</strong> The history file name can be set any time, however
 * only the action views created by {@link #onCreateActionView()} after setting
 * the file name will be backed by the provided file. Therefore, if you want to
 * use different history files for sharing specific types of content, every time
 * you change the history file {@link #setShareHistoryFileName(String)} you must
 * call {@link android.app.Activity#invalidateOptionsMenu()} to recreate the
 * action view. You should <strong>not</strong> call
 * {@link android.app.Activity#invalidateOptionsMenu()} from
 * {@link android.app.Activity#onCreateOptionsMenu(Menu)}."
 * <p>
 * <code>
 * private void doShare(Intent intent) {
 *     if (IMAGE.equals(intent.getMimeType())) {
 *         mShareActionProvider.setHistoryFileName(SHARE_IMAGE_HISTORY_FILE_NAME);
 *     } else if (TEXT.equals(intent.getMimeType())) {
 *         mShareActionProvider.setHistoryFileName(SHARE_TEXT_HISTORY_FILE_NAME);
 *     }
 *     mShareActionProvider.setIntent(intent);
 *     invalidateOptionsMenu();
 * }
 * <code>
 *
 * @param shareHistoryFile The share history file name.
 */
public void setShareHistoryFileName(String shareHistoryFile) {
    mShareHistoryFileName = shareHistoryFile;
    setActivityChooserPolicyIfNeeded();
}

/**
 * Sets an intent with information about the share action. Here is a
 * sample for constructing a share intent:
 * <p>
 * <pre>
 * <code>
 *  Intent shareIntent = new Intent(Intent.ACTION_SEND);
 *  shareIntent.setType("image/*");
 *  Uri uri = Uri.fromFile(new File(getFilesDir(), "foo.jpg"));
 *  shareIntent.putExtra(Intent.EXTRA_STREAM, uri.toString());
 * </pre>
 * </code>
 * </p>
 *
 * @param shareIntent The share intent.
 *
 * @see Intent#ACTION_SEND
 * @see Intent#ACTION_SEND_MULTIPLE
 */
public void setShareIntent(Intent shareIntent) {
    if (shareIntent != null) {
        final String action = shareIntent.getAction();
        if (Intent.ACTION_SEND.equals(action) || Intent.ACTION_SEND_MULTIPLE.equals(action)) {
            updateIntent(shareIntent);
        }
    }
    ActivityChooserModel dataModel = ActivityChooserModel.get(mContext,
            mShareHistoryFileName);
    dataModel.setIntent(shareIntent);
}

/**
 * Reusable listener for handling share item clicks.
 */
private class ShareMenuItemOnMenuItemClickListener implements OnMenuItemClickListener {
    @Override
    public boolean onMenuItemClick(MenuItem item) {
        ActivityChooserModel dataModel = ActivityChooserModel.get(mContext,
                mShareHistoryFileName);
        final int itemId = item.getItemId();
        Intent launchIntent = dataModel.chooseActivity(itemId);
        if (launchIntent != null) {
            final String action = launchIntent.getAction();
            if (Intent.ACTION_SEND.equals(action) ||
                    Intent.ACTION_SEND_MULTIPLE.equals(action)) {
                updateIntent(launchIntent);
            }
            mContext.startActivity(launchIntent);
        }
        return true;
    }
}

/**
 * Set the activity chooser policy of the model backed by the current
 * share history file if needed which is if there is a registered callback.
 */
private void setActivityChooserPolicyIfNeeded() {
    if (mOnShareListener == null) {
        return;
    }
    if (mOnChooseActivityListener == null) {
        mOnChooseActivityListener = new ShareActivityChooserModelPolicy();
    }
    ActivityChooserModel dataModel = ActivityChooserModel.get(mContext, mShareHistoryFileName);
    dataModel.setOnChooseActivityListener(mOnChooseActivityListener);
}

/**
 * Policy that delegates to the {@link OnShareTargetSelectedListener}, if such.
 */
private class ShareActivityChooserModelPolicy implements OnChooseActivityListener {
    @Override
    public boolean onChooseActivity(ActivityChooserModel host, Intent intent) {
        if (mOnShareListener != null) {
            boolean result = mOnShareListener.willHandleShareTarget(
                    ShareActionProvider.this, intent);
            return result;
        }
        return false;
    }
}

private void updateIntent(Intent intent) {
    if (Build.VERSION.SDK_INT >= 21) {
        // If we're on Lollipop, we can open the intent as a document
        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_DOCUMENT |
                Intent.FLAG_ACTIVITY_MULTIPLE_TASK);
    } else {
        // Else, we will use the old CLEAR_WHEN_TASK_RESET flag
        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET);
    }
}
}

我的 ShareActionProvider 类中有一个构造函数；

public ShareActionProvider(Context context) {
    super(context);
    mContext = context;
}

为什么它给我这个错误？我怎么解决这个问题。谢谢!

Answer 1

我将自定义 ActionShareProvider.class 重命名为 CustomActionShareProvider.class 并解决了问题。