RecyclerView 切换内容展示样式，每行3列展示缩略图和列表展示相互切换

效果：

主要实现方法是通过使用RecyclerView中的GridLayoutManager，通过setSpanCount()方法，设置每行1列或每行三列。点击切换按钮后通过adapter的notifyDateSetChange方法，刷新列表，重走getItemViewType，onBindViewHolder，onCreateViewHolder的逻辑。达到切换视图的显示方式的目的。
点击切换按钮执行的方法：

private class ChangeShowTypeListener implements View.OnClickListener {

        @Override
        public void onClick(View v) {
            if (gridLayoutManager.getSpanCount() == SPAN_COUNT_ONE) {
                gridLayoutManager.setSpanCount(SPAN_COUNT_THREE);

                //           user_homepage_change.setImageDrawable(getResources().getDrawable(R.mipmap.homepage_show_threepic));
                recyclerView.scrollToPosition(0);

                // loadData(2);
            } else {
                gridLayoutManager.setSpanCount(SPAN_COUNT_ONE);
                //              user_homepage_change.setImageDrawable(getResources().getDrawable(R.mipmap.homepage_show_onepic));
                recyclerView.scrollToPosition(0);
                //  loadData(2);
            }
            // ugcWebItemList.clear();

            homePageAdapter.notifyItemRangeChanged(0, homePageAdapter.getItemCount());

        }
    }

@Override
    public int getItemViewType(int position) {
      //  if (position == 0) return TYPE_HEADER;
        int spanCount = mLayoutManager.getSpanCount();
        if (spanCount == SPAN_COUNT_ONE) {
            return VIEW_TYPE_ONE;
        } else {
            return VIEW_TYPE_THREE;
        }
    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view;
       /* if (viewType == TYPE_HEADER) {
            view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_header_homepage, parent, false);
            return new HeaderViewHolder(view);
        }*/
        if (viewType == VIEW_TYPE_ONE) {
            view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_onepic_homepage, parent, false);
            return new HomePageOnePicViewHolder(view);
        } else {
            view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_threepic_homepage, parent, false);
            return new HomePageThreePicViewHolder(view);
        }
    }

    @Override
    public void onBindViewHolder(final ViewHolder holder, int position) {

        final UserHomePageBean userHomePageItem = userHomePageBeanList.get(position);
        if (holder.getItemViewType() == VIEW_TYPE_THREE) {
             HomePageThreePicViewHolder homePageThreePicViewHolder = (HomePageThreePicViewHolder) holder;
             //设置每张小图的宽高为屏幕宽度的1/3
            ViewGroup.LayoutParams layoutParams = homePageThreePicViewHolder.imageView.getLayoutParams();
            layoutParams.height = layoutParams.width = (ScreenUtils.getScreenWidth(mContext)) / 3;
            //设置图片之间的间隔           homePageThreePicViewHolder.imageView.setLayoutParams(layoutParams);
            if (position == 0 || position% 3 == 0) {
                homePageThreePicViewHolder.itemView.setPadding(0, 0,
                        ScreenUtils.dp2px(mContext, 2), ScreenUtils.dp2px(mContext, 3));
            } else if (position- 1 == 0 || (position- 1) % 3 == 0) {
                homePageThreePicViewHolder.itemView.setPadding(ScreenUtils.dp2px(mContext, 1), 0,
                        ScreenUtils.dp2px(mContext, 1), ScreenUtils.dp2px(mContext, 3));
            } else if ((position+ 1) % 3 == 0) {
                homePageThreePicViewHolder.itemView.setPadding(ScreenUtils.dp2px(mContext, 2),
                        0, 0, ScreenUtils.dp2px(mContext, 3));
            }
         ......
        } else if (holder.getItemViewType() == VIEW_TYPE_ONE) {
            HomePageOnePicViewHolder homePageOnePicViewHolder = (HomePageOnePicViewHolder) holder;
         ......
        }
    }

class ViewHolder extends RecyclerView.ViewHolder {

        public ViewHolder(View itemView) {
            super(itemView);
        }
    }

    class HomePageOnePicViewHolder extends ViewHolder {

        HomePageOnePicViewHolder(View itemView) {
            super(itemView);
          ......
        }
    }

    class HomePageThreePicViewHolder extends ViewHolder {

        HomePageThreePicViewHolder(View itemView) {
            super(itemView);
            imageView = (ImageView) itemView.findViewById(R.id.homepage_image);
            imageTag = (ImageView) itemView.findViewById(R.id.homepage_image_tag);
        }
    }

两种样式的layout：
每行3图样式：

<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    >
    <ImageView
        android:id="@+id/homepage_image"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:scaleType="centerCrop"
    />

    <ImageView
        android:id="@+id/homepage_image_tag"
        android:layout_width="25dp"
        android:layout_height="20dp"
        android:layout_alignParentRight="true"
        android:layout_alignParentTop="true"
        android:layout_marginRight="8dp"
        android:layout_marginTop="8dp"
        android:src="@mipmap/homepage_video"
        />

RelativeLayout>

每行1图样式：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/ll_root"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    <LinearLayout
        android:id="@+id/homepage_rl_item"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#ffffff"
        android:orientation="vertical"
        android:paddingTop="16dp">

        .... 图片上面的控件....

        <RelativeLayout
            android:id="@+id/homepage_rl_image"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_below="@+id/homepage_txt_content"
            android:layout_marginTop="12dp">

            <ImageView
                android:id="@+id/homepage_image"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:scaleType="centerCrop" />

            <TextView
                android:id="@+id/homepage_image_toolong"
                android:layout_width="match_parent"
                android:layout_height="30dp"
                android:layout_alignParentBottom="true"
                android:background="#88000000"
                android:gravity="center"
                android:text="@string/view_full_image"
                android:textColor="#ffffff"
                android:textSize="12sp"
                android:visibility="gone" />

            <TextView
                android:id="@+id/homepage_txt_count"
                android:layout_width="30dp"
                android:layout_height="30dp"
                android:layout_alignParentBottom="true"
                android:layout_alignParentRight="true"
                android:background="#88000000"
                android:gravity="center"
                android:padding="7dp"
                android:text="5P"
                android:textColor="#ffffff"
                android:textSize="12sp" />
        RelativeLayout>

        <com.gif.gifchannel.videoplayer.TextureVideoPlayer
            android:id="@+id/video_player"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_below="@+id/homepage_txt_content"
            android:layout_marginTop="12dp"
            android:visibility="gone" />


        <LinearLayout
            android:id="@+id/ll_operate"
            android:layout_width="match_parent"
            android:layout_height="40dp"
            android:layout_marginTop="8dp"
            android:gravity="center_vertical"
            android:orientation="horizontal"
            android:paddingLeft="8dp"
            android:paddingRight="8dp">

           ...图片下面的控件...
        LinearLayout>
    LinearLayout>

LinearLayout>