RecyclerView.Adapter在单行中显示2个项目（如何更改它）

Question

所以我正在一个已经有一些代码的项目中工作。我想更改适配器项的显示方式。

现在每行有2个项目。 我想做的是每行只有一项。

这里是图像布局现在的样子。

每行显示2个项目，而我只需要显示1个项目。

这是xml上的代码

Item xml

<com.inthessaloniki.cityguide.view.SelectorRelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/fragment_poi_list_item"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:listSelector="@drawable/selector_clickable_item_bg_inverse">
<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <ImageView
        android:id="@+id/fragment_poi_list_item_image"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:scaleType="fitXY"/>

</RelativeLayout>

列出xml

<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:animateLayoutChanges="true">

<LinearLayout
    android:id="@+id/container_content"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/fragment_poi_list_recycler"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:scrollbars="vertical"
        android:background="@color/global_bg_front" />

    <com.google.android.gms.ads.AdView
        android:id="@+id/fragment_poi_list_adview"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        app:adUnitId="@string/admob_unit_id_poi_list"
        app:adSize="BANNER" />

</LinearLayout>

<include
    layout="@layout/placeholder_progress"
    android:id="@+id/container_progress"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:visibility="gone" />

<include
    layout="@layout/placeholder_offline"
    android:id="@+id/container_offline"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:visibility="gone" />

<include
    layout="@layout/placeholder_empty"
    android:id="@+id/container_empty"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:visibility="gone" />

ListAdapter代码

public class SubCategoryListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder>
{
    public static final int VIEW_TYPE_POI = 1;
    public static final int VIEW_TYPE_IMAGE_FOOTER = 2;
    public static final int VIEW_TYPE_FOOTER = 3;

    private List<CategoryModel> mPoiList;
    private List<Object> mFooterList;
    private PoiViewHolder.OnItemClickListener mListener;
    private int mGridSpanCount;
    private Location mLocation;
    private boolean mAnimationEnabled = true;
    private int mAnimationPosition = -1;
    private ImageLoader mImageLoader = ImageLoader.getInstance();
    private DisplayImageOptions mDisplayImageOptions;
    private ImageLoadingListener mImageLoadingListener;


    //Ares
    private long mCategory;


    public SubCategoryListAdapter(List<CategoryModel> poiList, List<Object> footerList, PoiViewHolder.OnItemClickListener listener, int gridSpanCount, Location location, long category)
    {
        mPoiList = poiList;
        mFooterList = footerList;
        mListener = listener;
        mGridSpanCount = gridSpanCount;
        mLocation = location;

        //Ares
        mCategory = category;

        // image caching options
        mDisplayImageOptions = new DisplayImageOptions.Builder()
                .showImageOnLoading(android.R.color.transparent)
                .showImageForEmptyUri(R.drawable.placeholder_photo)
                .showImageOnFail(R.drawable.placeholder_photo)
                .cacheInMemory(true)
                .cacheOnDisk(true)
                .displayer(new SimpleBitmapDisplayer())
                .build();
        mImageLoadingListener = new AnimateImageLoadingListener();
    }


    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType)
    {
        LayoutInflater inflater = LayoutInflater.from(parent.getContext());

        // inflate view and create view holder
        View view;
        if(viewType== VIEW_TYPE_POI)
        {
            if(mCategory == -4) {
                view = inflater.inflate(R.layout.fragment_poi_list_item_home, parent, false);
            }
            else
            {
                view = inflater.inflate(R.layout.fragment_poi_list_item, parent, false);
            }
            return new PoiViewHolder(view, mListener, mImageLoader, mDisplayImageOptions, mImageLoadingListener, mCategory);
        }
        else if(viewType==VIEW_TYPE_IMAGE_FOOTER)
        {
            view = inflater.inflate(R.layout.footer_image_layout, parent, false);
            return new ImageFooterViewHolder(view, mListener);
        }
        else if(viewType==VIEW_TYPE_FOOTER)
        {
            view = inflater.inflate(R.layout.fragment_poi_list_footer, parent, false);
            return new FooterViewHolder(view);
        }
        else
        {
            throw new RuntimeException("There is no view type that matches the type " + viewType);
        }
    }


    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder viewHolder, int position)
    {
        // bind data
        if(viewHolder instanceof PoiViewHolder)
        {
            // entity
            CategoryModel poi = mPoiList.get(getPoiPosition(position));

            // render view
            if(poi != null)
            {
                ((PoiViewHolder) viewHolder).bindData(poi, mLocation, mCategory);
            }
        }
        else if(viewHolder instanceof FooterViewHolder)
        {
            // entity
            Object object = mFooterList.get(getFooterPosition(position));

            // render view
            if(object != null)
            {
                ((FooterViewHolder) viewHolder).bindData(object);
            }
        }

        // set item margins
        setItemMargins(viewHolder.itemView, position);

        // set animation
        setAnimation(viewHolder.itemView, position);
    }


    @Override
    public int getItemCount()
    {
        int size = 0;
        if(mPoiList !=null) size += mPoiList.size();
        if(mFooterList!=null) size += mFooterList.size();
        if(mFooterList!=null) size += 1; //ImageFooter
        return size;
    }

    @Override
    public int getItemViewType(int position)
    {
        int pois = mPoiList.size();
        int footers = mFooterList.size();
        int imageFooter = 1;

        if(position < pois) return VIEW_TYPE_POI;
        else if(position < pois+imageFooter) return VIEW_TYPE_IMAGE_FOOTER;
        else if(position < pois+imageFooter+footers) return VIEW_TYPE_FOOTER;
        else return -1;
    }

    public int getPoiCount()
    {
        if(mPoiList !=null) return mPoiList.size();
        return 0;
    }


    public int getFooterCount()
    {
        if(mFooterList!=null) return mFooterList.size();
        return 0;
    }


    public int getPoiPosition(int recyclerPosition)
    {
        return recyclerPosition;
    }


    public int getFooterPosition(int recyclerPosition)
    {
        return recyclerPosition - getPoiCount();
    }


    public int getRecyclerPositionByPoi(int poiPosition)
    {
        return poiPosition;
    }


    public int getRecyclerPositionByFooter(int footerPosition)
    {
        return footerPosition + getPoiCount();
    }


    public void refill(List<CategoryModel> poiList, List<Object> footerList, PoiViewHolder.OnItemClickListener listener, int gridSpanCount, Location location)
    {
        mPoiList = poiList;
        mFooterList = footerList;
        mListener = listener;
        mGridSpanCount = gridSpanCount;
        mLocation = location;
        notifyDataSetChanged();
    }


    public void stop()
    {

    }


    public void setLocation(Location location)
    {
        mLocation = location;
    }


    public void setAnimationEnabled(boolean animationEnabled)
    {
        mAnimationEnabled = animationEnabled;
    }


    private void setAnimation(final View view, int position)
    {
        if(mAnimationEnabled && position>mAnimationPosition)
        {
            view.setScaleX(0f);
            view.setScaleY(0f);
            view.animate()
                    .scaleX(1f)
                    .scaleY(1f)
                    .setDuration(300)
                    .setInterpolator(new DecelerateInterpolator());

            mAnimationPosition = position;
        }
    }


    private void setItemMargins(View view, int position)
    {
        int height = 0;
        if(mCategory != -4)
            height = (int) CityGuideApplication.getContext().getResources().getDimension(R.dimen.fragment_poi_list_recycler_item_size);
        int marginTop = 0;

        if(position<mGridSpanCount)
        {
            TypedArray a = CityGuideApplication.getContext().obtainStyledAttributes(null, new int[]{android.R.attr.actionBarSize}, 0, 0);
            marginTop = (int) a.getDimension(0, 0);
            a.recycle();

            if(mCategory != -4)
                height += marginTop;
        }

        ViewGroup.MarginLayoutParams marginParams = (ViewGroup.MarginLayoutParams) view.getLayoutParams();
        marginParams.setMargins(0, marginTop, 0, 0);

        ViewGroup.LayoutParams layoutParams = view.getLayoutParams();
        if(mCategory != -4)
            layoutParams.height = height;
    }


    public static final class PoiViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener
    {
        private TextView nameTextView;
        private TextView distanceTextView;
        private ImageView imageView;
        private OnItemClickListener mListener;
        private ImageLoader mImageLoader;
        private DisplayImageOptions mDisplayImageOptions;
        private ImageLoadingListener mImageLoadingListener;


        public interface OnItemClickListener
        {
            public void onItemClick(View view, int position, long id, int viewType);
        }


        public PoiViewHolder(View itemView, OnItemClickListener listener, ImageLoader imageLoader, DisplayImageOptions displayImageOptions, ImageLoadingListener imageLoadingListener, long category)
        {
            super(itemView);
            mListener = listener;
            mImageLoader = imageLoader;
            mDisplayImageOptions = displayImageOptions;
            mImageLoadingListener = imageLoadingListener;

            // set listener
            itemView.setOnClickListener(this);

            // find views
            if(category == -4)
            {
                Log.d("Category Status: ", String.valueOf(category));
            }
            else
            {
                nameTextView = (TextView) itemView.findViewById(R.id.fragment_poi_list_item_name);
                distanceTextView = (TextView) itemView.findViewById(R.id.fragment_poi_list_item_distance);

                distanceTextView.setVisibility(View.GONE);
            }
            imageView = (ImageView) itemView.findViewById(R.id.fragment_poi_list_item_image);



        }


        @Override
        public void onClick(View view)
        {
            mListener.onItemClick(view, getPosition(), getItemId(), getItemViewType());
        }


        public void bindData(CategoryModel subCategory, Location location, long category)
        {
            if(category == -4)
            {

            }
            else
            {
                nameTextView.setText(subCategory.getName());
            }
            mImageLoader.displayImage(subCategory.getImage2(), imageView, mDisplayImageOptions, mImageLoadingListener);
//          if(location!=null)
//          {
//              LatLng myLocation = new LatLng(location.getLatitude(), location.getLongitude());
//              LatLng poiLocation = new LatLng(poi.getLatitude(), poi.getLongitude());
//              String distance = LocationUtility.getDistanceString(LocationUtility.getDistance(myLocation, poiLocation), LocationUtility.isMetricSystem());
//              distanceTextView.setText(distance);
//              distanceTextView.setVisibility(View.VISIBLE);
//          }
//          else
//          {
//              distanceTextView.setVisibility(View.GONE);
//          }
        }
    }

    public static final class ImageFooterViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
        private PoiViewHolder.OnItemClickListener mListener;


        public interface OnItemClickListener {
            public void onItemClick(View view, int position, long id, int viewType);
        }


        public ImageFooterViewHolder(View itemView, PoiViewHolder.OnItemClickListener listener) {
            super(itemView);
            mListener = listener;

            // set listener
            itemView.setOnClickListener(this);
        }


        @Override
        public void onClick(View view) {
            mListener.onItemClick(view, getPosition(), getItemId(), getItemViewType());
        }


        public void bindData(PoiModel poi, Location location) {

        }
    }


    public static final class FooterViewHolder extends RecyclerView.ViewHolder
    {
        public FooterViewHolder(View itemView)
        {
            super(itemView);
        }


        public void bindData(Object object)
        {
            // do nothing
        }
    }
}

GritLayout

public class GridSpacingItemDecoration extends RecyclerView.ItemDecoration
{
    private int mSpacing;


    public GridSpacingItemDecoration(int spacingPixelSize)
    {
        mSpacing = spacingPixelSize;
    }


    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView recyclerView, RecyclerView.State state)
    {
        super.getItemOffsets(outRect, view, recyclerView, state);

        int position = recyclerView.getChildPosition(view);
        int spanCount = getSpanCount(recyclerView);
        int itemCount = recyclerView.getAdapter().getItemCount();

        // top offset
        if(position < spanCount)
        {
            outRect.top = mSpacing;
        }
        else
        {
            outRect.top = mSpacing/2;
        }

        // bottom offset
        if(itemCount%spanCount == 0 && position >= itemCount - spanCount)
        {
            outRect.bottom = mSpacing;
        }
        else if(itemCount%spanCount != 0 && position >= itemCount - itemCount%spanCount)
        {
            outRect.bottom = mSpacing;
        }
        else
        {
            outRect.bottom = mSpacing/2;
        }

        // left offset
        if(position%spanCount == 0)
        {
            outRect.left = mSpacing;
        }
        else
        {
            outRect.left = mSpacing/2;
        }

        // right offset
        if(position%spanCount == spanCount-1)
        {
            outRect.right = mSpacing;
        }
        else
        {
            outRect.right = mSpacing/2;
        }
    }


    private int getSpanCount(RecyclerView recyclerView)
    {
        if(recyclerView.getLayoutManager() instanceof GridLayoutManager)
        {
            GridLayoutManager gridLayoutManager = (GridLayoutManager) recyclerView.getLayoutManager();
            return gridLayoutManager.getSpanCount();
        }
        else
        {
            throw new IllegalStateException(this.getClass().getSimpleName() + " can only be used with a " + GridLayoutManager.class.getSimpleName());
        }
    }
}

我不认为问题出在XML文件中。它必须在代码中。我只是无法对其进行跟踪和修改...：S

我已经搜索了几个小时。

提前感谢！

Answer 1

您尚未将代码段设置为将LayoutManager设置为RecyclerView的位置。

似乎您正在使用GridLayoutManager：

RecyclerView.LayoutManager mLayoutManager = new GridLayoutManager(context, 2);
myRecyclerView.setLayoutManager(mLayoutManager);

尝试将其更改为LinearLayoutManager：

RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(context);    
myRecyclerView.setLayoutManager(mLayoutManager);