监听RecyclerView滑动到末端

效果图

实现

1. 添加滑动到末端的接口

package com.kongqw.recyclerviewdemo;

/**

 * Created by kongqw on 2016/2/14.

 */

public interface OnBottomListener {

    public void onBottom();

}

2. 重写RecyclerView.OnScrollListener

package com.kongqw.recyclerviewdemo;

import android.support.v7.widget.GridLayoutManager;

import android.support.v7.widget.LinearLayoutManager;

import android.support.v7.widget.RecyclerView;

import android.support.v7.widget.StaggeredGridLayoutManager;

/**

 * Created by kongqw on 2016/2/14.

 */

public class OnRecyclerViewScrollListener extends RecyclerView.OnScrollListener implements OnBottomListener {

    public enum LAYOUT_MANAGER_TYPE {

        LINEAR,

        GRID,

        STAGGERED_GRID

    }

    /**

     * layoutManager的类型（枚举）

     */

    protected LAYOUT_MANAGER_TYPE layoutManagerType;

    /**

     * 最后一个的位置

     */

    private int[] lastPositions;

    /**

     * 最后一个可见的item的位置

     */

    private int lastVisibleItemPosition;

    /**

     * 当前滑动的状态

     */

    private int currentScrollState = 0;

    @Override

    public void onScrolled(RecyclerView recyclerView, int dx, int dy) {

        super.onScrolled(recyclerView, dx, dy);

        RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();

        if (layoutManagerType == null) {

            if (layoutManager instanceof LinearLayoutManager) {

                layoutManagerType = LAYOUT_MANAGER_TYPE.LINEAR;

            } else if (layoutManager instanceof GridLayoutManager) {

                layoutManagerType = LAYOUT_MANAGER_TYPE.GRID;

            } else if (layoutManager instanceof StaggeredGridLayoutManager) {

                layoutManagerType = LAYOUT_MANAGER_TYPE.STAGGERED_GRID;

            } else {

                throw new RuntimeException("Unsupported LayoutManager used. Valid ones are LinearLayoutManager, GridLayoutManager and StaggeredGridLayoutManager");

            }

        }

        switch (layoutManagerType) {

            case LINEAR:

                lastVisibleItemPosition = ((LinearLayoutManager) layoutManager).findLastVisibleItemPosition();

                break;

            case GRID:

                lastVisibleItemPosition = ((GridLayoutManager) layoutManager).findLastVisibleItemPosition();

                break;

            case STAGGERED_GRID:

                StaggeredGridLayoutManager staggeredGridLayoutManager = (StaggeredGridLayoutManager) layoutManager;

                if (lastPositions == null) {

                    lastPositions = new int[staggeredGridLayoutManager.getSpanCount()];

                }

                staggeredGridLayoutManager.findLastVisibleItemPositions(lastPositions);

                lastVisibleItemPosition = findMax(lastPositions);

                break;

        }

    }

    @Override

    public void onScrollStateChanged(RecyclerView recyclerView, int newState) {

        super.onScrollStateChanged(recyclerView, newState);

        currentScrollState = newState;

        RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();

        int visibleItemCount = layoutManager.getChildCount();

        int totalItemCount = layoutManager.getItemCount();

        if ((visibleItemCount > 0 && currentScrollState == RecyclerView.SCROLL_STATE_IDLE && (lastVisibleItemPosition) >= totalItemCount - 1)) {

            onBottom();

        }

    }

    @Override

    public void onBottom() {

        // Log.d(TAG, "滑动到了底部");

    }

    private int findMax(int[] lastPositions) {

        int max = lastPositions[0];

        for (int value : lastPositions) {

            if (value > max) {

                max = value;

            }

        }

        return max;

    }

}

3. 回调

recyclerView.addOnScrollListener(new OnRecyclerViewScrollListener() {

    @Override

    public void onBottom() {

        super.onBottom();

        Toast.makeText(getApplicationContext(), "滑动到了末端", Toast.LENGTH_SHORT).show();

    }

});