RecyclerView得内容不可见

Question

我正在尝试创建一个ListView，它的每一行都是一个水平滚动列表。早些时候，我使用的是HorizontalScrollView，但我需要一个可以回收视图的布局。所以我使用了RecyclerView，但是现在RecyclerView的内容不可见了。

下面是我的垂直ListView适配器：

public class FeedAdapter extends BaseAdapter {
    private Context context;
    private FeedItem feedItem;
    private static LayoutInflater inflater = null;
    private Picasso picasso;
    Typeface opensans;

    public FeedAdapter(Context context, FeedItem feedItem) {
        this.context = context;
        this.feedItem = feedItem;
        inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        opensans = Typeface.createFromAsset(context.getAssets(), "fonts/OpenSans-Regular.ttf");
        OkHttpClient okHttpClient = new OkHttpClient();
        picasso = new Picasso.Builder(context)
                .downloader(new OkHttpDownloader(okHttpClient))
                .build();
    }


    @Override
    public int getCount() {
        return feedItem.getFeedList().size();
    }

    @Override
    public FeedList getItem(int position) {
        return feedItem.getFeedList().get(position);
    }

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

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View view = convertView;
        final FeedRowViewHolder rowViewHolder;

        if (view == null) {
            view = inflater.inflate(R.layout.feed_row, parent, false);
            rowViewHolder = new FeedRowViewHolder(view);
            view.setTag(rowViewHolder);
        } else {
            rowViewHolder = (FeedRowViewHolder) view.getTag();
        }

        final FeedList feedList = feedItem.getFeedList().get(position);

        picasso.with(context)
                .load(feedList.getThumbnailUrl())
                .resize(120, 120)
                .centerCrop()
                .into(rowViewHolder.galleryThumb);
        rowViewHolder.galleryThumb.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String api_url = feedList.getUrl();
                String delims = "/";
                String[] tokens = api_url.split(delims);
                String thumbId = tokens[5];
                ((HomeActivity) context).changeIntent(thumbId);
            }
        });

        rowViewHolder.galleryName.setText(feedList.getGalleryName());
        rowViewHolder.galleryName.setTypeface(opensans);
        rowViewHolder.galleryName.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String api_url = feedList.getUrl();
                String delims = "/";
                String[] tokens = api_url.split(delims);
                String thumbId = tokens[5];
                ((HomeActivity) context).changeIntent(thumbId);
            }
        });

        rowViewHolder.timestamp.setText(feedList.getCreatedDate());
        rowViewHolder.timestamp.setTypeface(opensans);

        rowViewHolder.followButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                picasso.with(context)
                        .load(R.drawable.cta_button_follow_secondary_state)
                        .into(rowViewHolder.followButton);
            }
        });

        LinearLayoutManager layoutManager = new LinearLayoutManager(context, LinearLayoutManager.HORIZONTAL, false);
        rowViewHolder.recyclerView.setLayoutManager(layoutManager);
        FeedItemAdapter adapter = new FeedItemAdapter(context, feedList.getPhotos());
        rowViewHolder.recyclerView.setAdapter(adapter);

        return view;
    }

    static class FeedRowViewHolder {
        @Bind(R.id.imageView75)
        ImageView galleryThumb;
        @Bind(R.id.textView65)
        TextView galleryName;
        @Bind(R.id.textView66)
        TextView timestamp;
        @Bind(R.id.imageView162)
        ImageView followButton;
        @Bind(R.id.recyclerView)
        RecyclerView recyclerView;

        public FeedRowViewHolder(View view) {
            ButterKnife.bind(this, view);
        }
    }
}

下面是我的水平回收视图适配器：

public class FeedItemAdapter extends RecyclerView.Adapter<FeedItemAdapter.ViewHolder> {
    private List<Photo> list;
    private Context context;
    private Picasso picasso;
    Typeface opensans;

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.feed_item, parent, false);
        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(final ViewHolder holder, int position) {
        final Photo photo = getValueAt(position);

        picasso.with(context)
                .load(photo.getPhotoUrl())
                .resize(1020, 768)
                .centerCrop()
                .into(holder.image);
        holder.image.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String photo_url = photo.getPhoto();
                String delims = "/";
                String[] tokens = photo_url.split(delims);
                String photoId = tokens[5];
                ((HomeActivity) context).setBackImage(photoId);
            }
        });

        picasso.with(context)
                .load(photo.getProfilePic())
                .resize(120, 120)
                .centerCrop()
                .transform(new CircleTransform())
                .into(holder.profilePic);
        holder.profilePic.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String user_url = photo.getOwner();
                String delims = "/";
                String[] tokens = user_url.split(delims);
                String photoId = tokens[5];
                ((HomeActivity) context).showUserProfile(photoId);
            }
        });

        holder.commentButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                ((HomeActivity) context).showComments();
            }
        });

        holder.fiveImage.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                ((HomeActivity) context).showLikes();
            }
        });

        holder.commentImage.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                ((HomeActivity) context).showComments();
            }
        });

        holder.username.setText(photo.getUserName());
        holder.username.setTypeface(opensans);

        holder.userFives.setText(Integer.toString(photo.getUserFives()) + " Fives");
        holder.userFives.setTypeface(opensans);

        holder.caption.setText(photo.getCaption());
        holder.caption.setTypeface(opensans);

        final int[] fives = {photo.getPhotoFives()};
        holder.numFives.setText(Integer.toString(photo.getPhotoFives()));
        holder.numFives.setTypeface(opensans);

        holder.numComments.setText(Integer.toString(photo.getNumComments()));
        holder.numComments.setTypeface(opensans);

        final boolean[] liked = {false};
        holder.fiveButton.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View view, MotionEvent motionEvent) {
                if (motionEvent.getAction() == MotionEvent.ACTION_DOWN) {
                    holder.fiveButton.setText("Hi Fiveeed!");
                    holder.fiveButton.setTypeface(opensans);
                    holder.fiveButton.setTextColor(Color.parseColor("#FAC80A"));

                    picasso.with(context)
                            .load(R.drawable.cta_ic_five_pressed_state)
                            .into(holder.fiveImage);
                }
                if (motionEvent.getAction() == MotionEvent.ACTION_UP) {
                    holder.fiveButton.setText("Five This!");
                    holder.fiveButton.setTypeface(opensans);
                    holder.fiveButton.setTextColor(Color.parseColor("#707070"));

                    picasso.with(context)
                            .load(R.drawable.user_profile_activity_1_ic_five_count)
                            .into(holder.fiveImage);
                }
                if (motionEvent.getAction() == MotionEvent.ACTION_MOVE) {
                    holder.fiveButton.setText("Five This!");
                    holder.fiveButton.setTypeface(opensans);
                    holder.fiveButton.setTextColor(Color.parseColor("#707070"));

                    picasso.with(context)
                            .load(R.drawable.user_profile_activity_1_ic_five_count)
                            .into(holder.fiveImage);
                }
                return false;
            }
        });
        holder.fiveButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if (liked[0] == false) {
                    holder.fiveButton.setText("Hi Fived!");
                    holder.fiveButton.setTypeface(opensans);
                    holder.fiveButton.setTextColor(Color.parseColor("#FAC80A"));

                    holder.numFives.setText(Integer.toString(fives[0] + 1));
                    fives[0] = fives[0] + 1;

                    picasso.with(context)
                            .load(R.drawable.cta_ic_five_pressed_state)
                            .into(holder.fiveImage);

                    liked[0] = true;
                } else {
                    holder.fiveButton.setText("Five This!");
                    holder.fiveButton.setTypeface(opensans);
                    holder.fiveButton.setTextColor(Color.parseColor("#707070"));

                    holder.numFives.setText(Integer.toString(fives[0] - 1));
                    fives[0] = fives[0] - 1;

                    picasso.with(context)
                            .load(R.drawable.user_profile_activity_1_ic_five_count)
                            .into(holder.fiveImage);

                    liked[0] = false;
                }
            }
        });
    }

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

    public Photo getValueAt(int position) {
        return list.get(position);
    }

    public static class ViewHolder extends RecyclerView.ViewHolder {
        @Bind(R.id.imageView86)
        ImageView image;
        @Bind(R.id.imageView76)
        ImageView profilePic;
        @Bind(R.id.textView67)
        TextView username;
        @Bind(R.id.textView68)
        TextView userFives;
        @Bind(R.id.textView1)
        TextView caption;
        @Bind(R.id.textView69)
        TextView fiveButton;
        @Bind(R.id.textView71)
        TextView commentButton;
        @Bind(R.id.imageView77)
        ImageView fiveImage;
        @Bind(R.id.textView72)
        TextView numFives;
        @Bind(R.id.imageView120)
        ImageView commentImage;
        @Bind(R.id.textView73)
        TextView numComments;

        public ViewHolder(View view) {
            super(view);
            ButterKnife.bind(this, view);
        }

    }

    public FeedItemAdapter(Context context, List<Photo> list) {
        this.context = context;
        this.list = list;
        opensans = Typeface.createFromAsset(context.getAssets(), "fonts/OpenSans-Regular.ttf");
        OkHttpClient okHttpClient = new OkHttpClient();
        picasso = new Picasso.Builder(context)
                .downloader(new OkHttpDownloader(okHttpClient))
                .build();
    }
}

下面是ListView行的布局：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/scroller_placeholder"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#231f20"
    android:orientation="vertical">


    <LinearLayout
        android:id="@+id/linearLayout7"
        android:background="#343031"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

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

            <ImageView
                android:id="@+id/imageView75"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerVertical="true"
                android:paddingRight="5dp"
                android:src="@drawable/user_profile_activity_1_img_gallery_1_icon"
                android:layout_marginTop="10dp"
                android:layout_marginBottom="10dp"
                android:layout_marginLeft="10dp" />

            <LinearLayout
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerVertical="true"
                android:layout_toRightOf="@+id/imageView75"
                android:orientation="vertical"
                android:paddingLeft="5dp">

                <TextView
                    android:id="@+id/textView65"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:alpha="0.8"
                    android:paddingBottom="2dp"
                    android:text="Wilderness"
                    android:textColor="#FFFFFF" />

                <TextView
                    android:id="@+id/textView66"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:paddingTop="2dp"
                    android:text="2 hrs."
                    android:textAppearance="?android:attr/textAppearanceSmall"
                    android:textColor="#707070"
                    android:textSize="12sp" />
            </LinearLayout>

            <ImageView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/imageView162"
                android:src="@drawable/cta_button_follow_default_state"
                android:layout_alignParentEnd="true"
                android:layout_marginRight="20dp"
                android:layout_centerVertical="true" />
        </RelativeLayout>
    </LinearLayout>

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recyclerView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</LinearLayout>

当我使用HorizontalScrollView时，每一行的项都显示得非常好，但recyclerView的内容没有显示出来。我想不出问题出在哪里。如有任何帮助，我们将不胜感激。

Answer 1

正如Icetea先生所说，您需要将布局高度设置为特定的数量。您可以获取显示项的高度，并将其传递给layout-height参数。

https://developer.android.com/reference/android/widget/linearlayout.layoutparams.html动态添加layoutparams的文档。

Answer 2

我认为您的问题在这里recyclerView的android:layout_height=“wrap_content”。尝试将此属性设置为特定值。

更新

Android支持库23.2的新版本：

RecyclerView小部件为创建列表和网格以及支持动画提供了一个高级而灵活的基础。这个版本为LayoutManager API带来了一个令人兴奋的新特性：自动测量！这允许RecyclerView根据其内容的大小调整自身的大小。这意味着以前不可用的场景，例如为RecyclerView的一个维度使用WRAP_CONTENT现在是可能的。您会发现所有内置的LayoutManager现在都支持自动测量。