RecyclerView 上拉加载的实现

先看效果图：

实现：

使用HeaderAndFooterRecyclerView添加Footer实现上拉加载。

1.compile

    compile  'com.takwolf.android:hf-recyclerview:0.1.1'

2.使用

使用方法与RecylerView 相同，只是多了两个方法：addHeader /addFooter。

xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/com_bg_gray_eeeeee"
    android:orientation="vertical">

    <com.takwolf.android.hfrecyclerview.HeaderAndFooterRecyclerView
        android:id="@+id/acty_allproduct_rv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
LinearLayout>

java

     rv = (HeaderAndFooterRecyclerView) findViewById(R.id.acty_allproduct_rv);
     rv.setLayoutManager(new LinearLayoutManager(this)); 
     adapter = new AllProductAdapter(AllProductActivity.this, list);
     rv.setAdapter(adapter);
     rv.addOnScrollListener(new LoadMore.ForRecyclerView(AllProductActivity.this));

LoadMore

辅助类，实现滑动到底部，回调OnScrollListentrer接口中的方法

public class LoadMore {

    private LoadMore(){

    }


    public static  class  ForRecyclerView extends  RecyclerView.OnScrollListener{


        private  int mLastVisiblePostion=-1;

        private OnLoadMoreListener loadMoreListener;

        public ForRecyclerView(OnLoadMoreListener loadMoreListener) {
            this.loadMoreListener = loadMoreListener;
        }


        @Override
        public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
            super.onScrollStateChanged(recyclerView, newState);

            View firstView  =recyclerView.getChildAt(0);


            int top=firstView.getTop();
            int  topEdge=recyclerView.getPaddingTop();
            //判断RecyclerView 的itemView是否满屏,如果不满上啦不会触发加载更多

            boolean isFullScreen=topint itemCount=manager.getItemCount();


            if (newState==RecyclerView.SCROLL_STATE_IDLE&&mLastVisiblePostion==(itemCount-1)&&isFullScreen){
                //最后一个item的时候,显示加载更多,
                //添加LoadMore布局

                loadMoreListener.showLoadMore();

                loadMoreListener.onLoadMore();
            }


        }

        @Override
        public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
            super.onScrolled(recyclerView, dx, dy);

            RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
            if (layoutManager instanceof LinearLayoutManager) {
                mLastVisiblePostion = ((LinearLayoutManager) layoutManager).findLastVisibleItemPosition();
            } else if (layoutManager instanceof GridLayoutManager) {
                mLastVisiblePostion = ((GridLayoutManager) layoutManager).findLastVisibleItemPosition();
            } else if (layoutManager instanceof StaggeredGridLayoutManager) {
                StaggeredGridLayoutManager staggeredGridLayoutManager = (StaggeredGridLayoutManager) layoutManager;
                int[] lastPositions = new int[staggeredGridLayoutManager.getSpanCount()];
                staggeredGridLayoutManager.findLastVisibleItemPositions(lastPositions);
                mLastVisiblePostion = findMax(lastPositions);
            }
        }
    }



    public interface OnLoadMoreListener {
        void showLoadMore();

        void onLoadMore();

        void hideLoadMore();
    }




    /**
     * 获取数组中的最大值
     *
     * @param lastPositions
     * @return
     */
    protected  static int findMax(int[] lastPositions) {
        int max = lastPositions[0];
        for (int value : lastPositions) {
            if (value > max) {
                max = value;
            }
        }
        return max;
    }

}

Activity全部代码

public class AllProductActivity extends DrawerBaseActivity  implements LoadMore.OnLoadMoreListener {

    private HeaderAndFooterRecyclerView rv;

    private List list;


    private AllProductAdapter adapter;

    private View load_more;

    private boolean loadMore=false;

    private boolean loadMoreFinish=true;

    @Override
    protected int getLayoutId() {
        return R.layout.activity_allproduct;
    }

    @Override
    protected void initView() {

        rv = (HeaderAndFooterRecyclerView) findViewById(R.id.acty_allproduct_rv);
        rv.setLayoutManager(new LinearLayoutManager(this));
        load_more = LayoutInflater.from(this).inflate(R.layout.load_more, null);

        //给控件设置弹性效果
        OverScrollDecoratorHelper.setUpOverScroll(rv, OverScrollDecoratorHelper.ORIENTATION_VERTICAL);

    }

    @Override
    public void initData() {


        list = new ArrayList<>();
        QpRetrofitManager.getInstance().getProductAll().subscribe(new BaseObServer() {
            @Override
            public void onHandleSuccess(ProductData productData) {


                if (Util.isNull(productData)||Util.isNull(productData.getBankProduct())||productData.getBankProduct().size()==0){

                }else {
                    list.addAll(productData.getBankProduct());
                    list.addAll(productData.getBankProduct());
                    list.addAll(productData.getBankProduct());
                    list.addAll(productData.getBankProduct());
                    list.addAll(productData.getBankProduct());
                    list.addAll(productData.getBankProduct());
                    list.addAll(productData.getBankProduct());
                    list.addAll(productData.getBankProduct());
                    list.addAll(productData.getBankProduct());
                    list.addAll(productData.getBankProduct());
                    list.addAll(productData.getBankProduct());
                    list.addAll(productData.getBankProduct());
                    list.addAll(productData.getBankProduct());
                    list.addAll(productData.getBankProduct());
                    list.addAll(productData.getBankProduct());

                    adapter = new AllProductAdapter(AllProductActivity.this, list);
                    rv.setAdapter(adapter);

                    rv.addOnScrollListener(new LoadMore.ForRecyclerView(AllProductActivity.this));
                }
            }
        });


    }

    @Override
    protected void initListener() {
        //让RecyclerView  有弹性效果

//        OverScrollDecoratorHelper.setUpOverScroll(rv, OverScrollDecoratorHelper.ORIENTATION_VERTICAL);

    }


    public static void actionStart(Context context) {
        Intent intent = new Intent(context, AllProductActivity.class);

        context.startActivity(intent);
    }

    @Override
    public void showLoadMore() {

        LogUtils.e("显示加载更多");
        ViewGroup parent = (ViewGroup) load_more.getParent();
        if (parent != null) {
            parent.removeView(load_more);
        }
        rv.addFooterView(load_more);
        ViewGroup.LayoutParams params = load_more.getLayoutParams();
        params.width = ViewGroup.LayoutParams.MATCH_PARENT;
        params.height = ViewGroup.LayoutParams.MATCH_PARENT;
        load_more.setLayoutParams(params);
    }

    @Override
    public void onLoadMore() {

        LogUtils.e("加载更多");
        if (!loadMoreFinish) return;
        if (isLoadMore()){
            //不显示加载更多
            hideLoadMore();
        }else {

            //判读是否剩下的为0
            if (Util.isNull(list) || list.size() == 0) {

                rv.postDelayed(new Runnable() {
                    @Override
                    public void run() {
                        hideLoadMore();
                        //没有更多了布局
//                        setNoMoreView();
                        loadMore = false;
                        loadMoreFinish = true;
                    }
                }, 2000);

            } else if (list.size() < 10) {
                rv.postDelayed(new Runnable() {
                    @Override
                    public void run() {
                        hideLoadMore();
                        //上拉加载添加评论
                        adapter.addReplyListAndNotify(list);
                        //没有更多了布局
//                        setNoMoreView();
                        loadMore = false;
                        loadMoreFinish = true;
                    }
                }, 2000);
            } else {
                rv.postDelayed(new Runnable() {
                    @Override
                    public void run() {
                        hideLoadMore();
                        //上拉加载添加评论
                        adapter.addReplyListAndNotify(list);
                        loadMoreFinish = true;
                    }
                }, 2000);
            }

        }

    }

    @Override
    public void hideLoadMore() {
        rv.removeFooterView(load_more);
    }

    public boolean isLoadMore() {
        return loadMore;
    }
}

Demo 地址

以上便可以实现上拉加载的效果，上拉加载布局可以自定义。