java - 使用 RecyclerAdapter 的 Facebook 原生广告

Question

我正在尝试通过将它们作为替代 View 包含在我的 RecyclerAdapter 中来实现 Facebook 原生广告。有没有人有这方面的经验？为了更好地衡量，我已经包括了我的整个类(class)。

public class FeedRecyclerAdapter extends LoadingRowRecyclerAdapter implements AdListener {

    private static final int VIEW_TYPE_FEED = 1;
    private static final int VIEW_TYPE_AD = 2;

    private final Context context;
    private final List<Feed> feedItems;
    private final ImageLoader feedItemImageLoader;
    private FeedItemClickListener feedItemClickListener;
    private boolean isLongPressed = false;

    private NativeAd nativeAd;
    private NativeAdsManager manager;
    View adView;

    public FeedRecyclerAdapter(Context context, List<Feed> feedItems, ImageLoader feedItemImageLoader, NativeAd nativeAd, NativeAdsManager manager) {
        this.context = context;
        this.feedItems = feedItems;
        this.feedItemImageLoader = feedItemImageLoader;
        this.nativeAd = nativeAd;
        this.manager = manager;
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        switch (viewType) {
            case VIEW_TYPE_FEED:
                return new FeedViewHolder(new FeedItemView(context));
            case VIEW_TYPE_AD:
                return new AdditionalHolder(LayoutInflater.from(context).inflate(R.layout.ad_test3, parent, false));
        }

        return super.onCreateViewHolder(parent, viewType);
    }

    public class AdditionalHolder extends RecyclerView.ViewHolder {
        protected LinearLayout templateContainer;
        protected ImageView blank_holder;
        private LinearLayout nativeAdContainer;
        private LinearLayout adView;
        private AdChoicesView adChoicesView;
        ImageView nativeAdIcon;
        TextView nativeAdTitle;
        TextView nativeAdBody;
        MediaView nativeAdMedia;
        TextView nativeAdSocialContext;
        Button nativeAdCallToAction;

        public AdditionalHolder(View view) {
            super(view);

            //// Add ad into the ad container.
            nativeAdContainer = (LinearLayout) view.findViewById(R.id.ad_unit);
            LayoutInflater inflater = LayoutInflater.from(context);
            adView = (LinearLayout) inflater.inflate(R.layout.ad_test3, nativeAdContainer, false);
            nativeAdContainer.addView(adView);

            // Create native UI using the ad metadata.
            nativeAdIcon = (ImageView) view.findViewById(R.id.native_ad_icon);
            nativeAdTitle = (TextView) view.findViewById(R.id.native_ad_title);
            nativeAdBody = (TextView) view.findViewById(R.id.native_ad_body);
            nativeAdMedia = (MediaView) view.findViewById(R.id.native_ad_media);
            nativeAdSocialContext = (TextView) view.findViewById(R.id.native_ad_social_context);
            nativeAdCallToAction = (Button) view.findViewById(R.id.native_ad_call_to_action);

        }
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder viewHolder, int position) {
        if (getItemViewType(position) == VIEW_TYPE_FEED) {
            bindFeedItemView((FeedViewHolder) viewHolder, position);
        } else if (getItemViewType(position) == VIEW_TYPE_AD) {

            AdditionalHolder new_holder = (AdditionalHolder) viewHolder;
            try {
                new_holder.templateContainer.removeViewInLayout(adView);
            } catch (Exception e) {
                e.printStackTrace();
            }
            nativeAd = manager.nextNativeAd();
            try {
                adView = NativeAdView.render(context, nativeAd, NativeAdView.Type.HEIGHT_300);
            } catch (NullPointerException e) {
                e.printStackTrace();
            }

            new_holder.templateContainer.addView(adView);
            new_holder.blank_holder.setVisibility(View.GONE);

            // Setting the Text.
            new_holder.nativeAdSocialContext.setText(nativeAd.getAdSocialContext());
            new_holder.nativeAdCallToAction.setText(nativeAd.getAdCallToAction());
            new_holder.nativeAdTitle.setText(nativeAd.getAdTitle());
            new_holder.nativeAdBody.setText(nativeAd.getAdBody());

            // Downloading and setting the ad icon.
            NativeAd.Image adIcon = nativeAd.getAdIcon();
            NativeAd.downloadAndDisplayImage(adIcon, new_holder.nativeAdIcon);

            // Download and setting the cover image.
            NativeAd.Image adCoverImage = nativeAd.getAdCoverImage();
            new_holder.nativeAdMedia.setNativeAd(nativeAd);

            // Add adChoices icon
            if (new_holder.adChoicesView == null) {
                new_holder.adChoicesView = new AdChoicesView(context, nativeAd, true);
                new_holder.adView.addView(new_holder.adChoicesView, 0);
            }

            nativeAd.registerViewForInteraction(new_holder.adView);

        }
    }

    // Differentiate between feedItem views and nativeAds
    @Override
    public int getItemViewType(int position) {
        int viewType = 1;
        if ((position % 9 == 0) && position != 1) viewType = 2;
        return viewType;
    }

    // For feedItems
    private void bindFeedItemView(FeedViewHolder viewHolder, int position) {
        final FeedItemView feedItemView = viewHolder.feedItemView;
        final Feed feedDesign = feedItems.get(position);

        // TODO we can probably conditionally show or hide these based on the type of feed item, same as in FeedActivitySingle
        feedItemView.showOrHideEditButton(true);
        feedItemView.showOrHideBuyButton(false);
        feedItemView.showOrHideFlipButton(false);
        feedItemView.showOrHidePriceText(false);

        // Set the results into TextViews
        feedItemView.setProductPriceText(String.valueOf(feedDesign.getDesign().getPrice()));
        feedItemView.setDownloadsText(String.valueOf(feedDesign.getDesign().getDownloadCount()));
        feedItemView.setLikesText(String.valueOf(feedDesign.getDesign().getLikesCount()));
        feedItemView.setUsernameText(feedDesign.getDesign().getAuthor().getUsername());
        feedItemView.setTimestampText(feedDesign.getTimestampText());
        feedItemView.getSaveImage().setImageResource(feedDesign.isInPersonalGallery() ? R.drawable.ic_action_saved : R.drawable.ic_not_saved);
        feedItemView.getLikeImage().setImageResource(feedDesign.isLiked() ? R.drawable.ic_action_like_feed_full : R.drawable.ic_action_like_feed);

        feedItemView.getTrashImage().setVisibility(ParseHelper.isCurrentUser(feedDesign.getDesign().getAuthor().getObjectId()) ? View.VISIBLE : View.GONE);
        feedItemView.getFeedSocialShareImage().setVisibility(View.VISIBLE);

        feedItemImageLoader.DisplayImage(feedDesign.getDesign().getCompressedImage().getUrl(), feedItemView.getImage(), feedItemView.getProgressBar());

        if(feedDesign.getDesign().getAuthor().getProfilePicture() != null) {
            feedItemImageLoader.DisplayImage(feedDesign.getDesign().getAuthor().getProfilePicture().getUrl(), feedItemView.getProfilePicture(), null); // TODO should this use profilePictureFileCache?
        } else {
            viewHolder.feedItemView.getProfilePicture().setImageResource(R.drawable.ic_anonymous);
        }

        SetCommentViews(feedItemView, feedDesign.getComments());
        SetClickListeners(feedItemView, feedDesign);
    }

    @Override
    protected int getContentDataSize() {
        return feedItems.size();
    }

    @Override
    protected int getViewType(int position) {
        if (position == 1) {
            return VIEW_TYPE_FEED;
        } else {
            return VIEW_TYPE_AD;
        }
    }

    // Facebook Ad methods
    @Override
    public void onError(Ad ad, AdError adError) {

    }

    @Override
    public void onAdLoaded(Ad ad) {

    }

    @Override
    public void onAdClicked(Ad ad) {

    }

    public void setFeedItemClickListener(FeedItemClickListener feedItemClickListener) {
        this.feedItemClickListener = feedItemClickListener;
    }

    private void SetCommentViews(FeedItemView feedItemView, List<Comment> comments) {

        feedItemView.getViewAllComments().setVisibility(View.VISIBLE);
        feedItemView.setViewAllComments("View more comments");

        // reset layouts to hidden
        feedItemView.getComment1Layout().setVisibility(View.GONE);
        feedItemView.getComment2Layout().setVisibility(View.GONE);
        feedItemView.getComment3Layout().setVisibility(View.GONE);

        if (comments == null || comments.size() == 0) {
            feedItemView.getViewAllComments().setVisibility(View.GONE);
            return;
        }

        // note these are meant to fall-through without break statements
        switch (comments.size()) {
            case 3:
                feedItemView.getComment3Layout().setVisibility(View.VISIBLE);
                feedItemView.setCommentUser3(comments.get(2).getAuthor().getUsername());
                feedItemView.setCommentText3(comments.get(2).getComment());
            case 2:
                feedItemView.getComment2Layout().setVisibility(View.VISIBLE);
                feedItemView.setCommentUser2(comments.get(1).getAuthor().getUsername());
                feedItemView.setCommentText2(comments.get(1).getComment());
            case 1:
                feedItemView.getComment1Layout().setVisibility(View.VISIBLE);
                feedItemView.setCommentUser1(comments.get(0).getAuthor().getUsername());
                feedItemView.setCommentText1(comments.get(0).getComment());
                break;
        }
    }

    private void SetClickListeners(final FeedItemView feedItemView, final Feed feedDesign) {

        // setup gesture detector with current view, view holder, and feed design
        final GestureDetector gestureDetector = new GestureDetector(context, new GestureListener(feedDesign, feedItemView));

        // set gesture detector on image view
        feedItemView.setImageTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View view, MotionEvent motionEvent) {
                if (motionEvent.getAction() == ACTION_UP){
                    if (isLongPressed){
                        isLongPressed = false;
                        feedItemClickListener.onMarkteFeedImageLongPressed_Release();
                        Log.d("anyTAG","Up");
                        return true;
                    }
                }
                if (motionEvent.getAction() == ACTION_MOVE){
                    return true;
                }
                return gestureDetector.onTouchEvent(motionEvent);
            }
        });

        feedItemView.setTrashImageClickListener(v -> {
            if (feedItemClickListener != null) {
                feedItemClickListener.onTrashClicked(feedDesign);
            }
        });

        feedItemView.setFeedSocialShareClickListener(v -> {
            if (feedItemClickListener != null) {
                try {
                    feedItemClickListener.onSocialShareClicked(feedDesign);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        });

        feedItemView.setLikeImageClickListener(v -> {
            if (feedItemClickListener != null) {
                feedItemClickListener.onLikeClicked(feedDesign, feedItemView);
            }
        });

        feedItemView.setSaveImageClickListener(v -> {
            if (feedItemClickListener != null) {
                feedItemClickListener.onSaveClicked(feedDesign, feedItemView);
            }
        });

        feedItemView.setAuthorClickListener(v -> {
            if (feedItemClickListener != null) {
                feedItemClickListener.onAuthorClicked(feedDesign);
            }
        });

        feedItemView.setCommentTextClickListener(v -> {
            if (feedItemClickListener != null) {
                feedItemClickListener.onCreateCommentClicked(feedDesign);
            }
        });

        feedItemView.setViewAllCommentsClickListener(v -> {
            if (feedItemClickListener != null) {
                feedItemClickListener.onCreateCommentClicked(feedDesign);
            }
        });

        feedItemView.setEditImageClickListener(v -> {
            if (feedItemClickListener != null) {
                feedItemClickListener.onCreateEditImageClicked(feedDesign);
            }
        });

        feedItemView.setCommentImageClickListener(v -> {
            if (feedItemClickListener != null) {
                feedItemClickListener.onCreateCommentClicked(feedDesign);
            }
        });

        feedItemView.setCommentUser1ClickListener(v -> {
            if (feedItemClickListener != null) {
                feedItemClickListener.onAuthorClicked(feedDesign.getComments().get(0).getAuthor().getObjectId());
            }
        });

        feedItemView.setCommentUser2ClickListener(v -> {
            if (feedItemClickListener != null) {
                feedItemClickListener.onAuthorClicked(feedDesign.getComments().get(1).getAuthor().getObjectId());
            }
        });

        feedItemView.setCommentUser3ClickListener(v -> {
            if (feedItemClickListener != null) {
                feedItemClickListener.onAuthorClicked(feedDesign.getComments().get(2).getAuthor().getObjectId());
            }
        });

        feedItemView.setProfilePictureClickListener(v -> {
            if (feedItemClickListener != null) {
                feedItemClickListener.onProfilePictureClicked(feedDesign);
            }
        });

    }

    class FeedViewHolder extends RecyclerView.ViewHolder {

        FeedItemView feedItemView;

        public FeedViewHolder(FeedItemView view) {
            super(view);
            this.feedItemView = view;
        }

    }

    // Gesture detector for double tap
    private class GestureListener extends GestureDetector.SimpleOnGestureListener {

        private Feed feedDesign;
        private FeedItemView feedItemView;

        public GestureListener(Feed feedDesign, FeedItemView feedItemView) {
            this.feedDesign = feedDesign;
            this.feedItemView = feedItemView;
        }

        @Override
        public boolean onDown(MotionEvent e) {
            return true;
        }

        @Override
        public boolean onDoubleTap(MotionEvent event) {
            Log.d("FeedRecyclerAdapter", feedDesign.getDesign().getCompressedImage().getUrl());

            if (feedItemClickListener != null) {
                feedItemClickListener.onImageDoubleTapped(feedDesign, feedItemView);
            }

            return true;
        }

        @Override
        public void onLongPress(MotionEvent event) {

            if (event.getAction() == ACTION_DOWN)
            {
                if (!isLongPressed){
                    isLongPressed = true;
                    feedItemClickListener.onMarketFeedImageLongPressed(feedDesign, feedDesign.getDisplayedSide());
                }
            }
        }
    }
}

我收到以下异常:

07-01 16:32:12.509 23168-23168/com.elgami.customizer E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.elgami.customizer, PID: 23168
java.lang.NullPointerException: Attempt to invoke virtual method 'com.facebook.ads.NativeAd com.facebook.ads.NativeAdsManager.nextNativeAd()' on a null object reference
at com.elgami.feed.FeedRecyclerAdapter.onBindViewHolder(FeedRecyclerAdapter.java:121)
at android.support.v7.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:5768)
at android.support.v7.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:5801)
at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5037)
at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:4913)
at android.support.v7.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:2029)
at android.support.v7.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1414)
at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1377)
at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:578)
at android.support.v7.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3260)
at android.support.v7.widget.RecyclerView.dispatchLayout(RecyclerView.java:3069)
at android.support.v7.widget.RecyclerView.onLayout(RecyclerView.java:3518)
at android.view.View.layout(View.java:16636)
at android.view.ViewGroup.layout(ViewGroup.java:5437)
at android.support.v4.widget.SwipeRefreshLayout.onLayout(SwipeRefreshLayout.java:598)
at android.view.View.layout(View.java:16636)
at android.view.ViewGroup.layout(ViewGroup.java:5437)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1743)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1586)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1495)
at android.view.View.layout(View.java:16636)
at android.view.ViewGroup.layout(ViewGroup.java:5437)
at android.widget.RelativeLayout.onLayout(RelativeLayout.java:1079)
at android.view.View.layout(View.java:16636)
at android.view.ViewGroup.layout(ViewGroup.java:5437)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:336)
at android.widget.FrameLayout.onLayout(FrameLayout.java:273)
at android.view.View.layout(View.java:16636)
at android.view.ViewGroup.layout(ViewGroup.java:5437)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1743)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1586)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1495)
at android.view.View.layout(View.java:16636)
at android.view.ViewGroup.layout(ViewGroup.java:5437)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:336)
at android.widget.FrameLayout.onLayout(FrameLayout.java:273)
at android.view.View.layout(View.java:16636)
at android.view.ViewGroup.layout(ViewGroup.java:5437)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1743)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1586)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1495)
at android.view.View.layout(View.java:16636)
at android.view.ViewGroup.layout(ViewGroup.java:5437)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:336)
at android.widget.FrameLayout.onLayout(FrameLayout.java:273)
at com.android.internal.policy.PhoneWindow$DecorView.onLayout(PhoneWindow.java:2678)
at android.view.View.layout(View.java:16636)
at android.view.ViewGroup.layout(ViewGroup.java:5437)
at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2171)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1931)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1107)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6013)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:858)
at android.view.Choreographer.doCallbacks(Choreographer.java:670)
at android.view.Choreographer.doFrame(Choreographer.java:606)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:844)
at android.os.Ha

首先，它似乎在提示这一行:

nativeAd = manager.nextNativeAd();

这是我的 FeedActivity 类的要点:

https://gist.github.com/anonymous/bd1b6afd21d27744a99970d3f51aa8a0

Answer 1

NullPointerException 当您尝试调用方法或访问对象引用的字段但该引用不包含有效对象时发生。一个简单的例子是:

String someString;
char firstChar = someString.charAt(0); // ERROR!

此代码会引发错误，因为在调用 charAt 时，someString 变量未引用有效的 String 实例。请注意，第一行没有创建 String 实例，它仅声明了一个可能指向 String 的变量>。事实上，这段代码等同于:

String someString = null;
char firstChar = someString.charAt(0);

有关 NullPointerException 的更多信息，它们发生的原因以及如何修复它们:see this question .

在您的情况下，错误是由 line 176 in FeedActivity 引起的:

feedRecyclerAdapter = new FeedRecyclerAdapter(this, feedItems, new ImageLoader(new FeedItemFileCache(this)), nativeAd, manager);

这里，manager 是FeedActivity 类的实例字段，定义在line 87 上。 :

public NativeAdsManager manager;

问题是这个字段从来没有被赋值:这个字段没有赋值(比如manager = ...)。因此，当执行第 176 行时，FeedRecyclerAdapter 接收 null 作为它的 manager 参数，并抛出一个 NullPointerException稍后在 onBindViewHolder 中尝试使用该 manager 时。

解决方案是在您的 FeedActivity 中创建一个有效的 NativeAdsManager 并将其分配给 manager，然后再传递给 FeedRecyclerAdapter。 From the Facebook documentation about NativeAdsManager ，这样的代码应该是这样的:

public class YourActivity extends Activity implements NativeAdsManager.Listener {

    private NativeAdsManager manager; 

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_layout);

        manager = new NativeAdsManager(this, "YOUR_PLACEMENT_ID", 5);
        manager.setListener(this);
        manager.loadAds();

    }
}