实现视频的播放和停止播放

     /**     * 停止播放     */    private void releaseVideo(View itemView) {        final VideoView videoView = itemView.findViewById(R.id.video_view);        final ImageView imgThumb = itemView.findViewById(R.id.img_thumb);        final ImageView imgPlay = itemView.findViewById(R.id.img_play);        videoView.stopPlayback();        imgThumb.animate().alpha(1).start();        imgPlay.animate().alpha(0f).start();    }    /**     * 开始播放     */    @TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR1)    private void playVideo(View itemView) {        final VideoView videoView = itemView.findViewById(R.id.video_view);        final ImageView imgPlay = itemView.findViewById(R.id.img_play);        final ImageView imgThumb = itemView.findViewById(R.id.img_thumb);        final RelativeLayout rootView = itemView.findViewById(R.id.root_view);        final MediaPlayer[] mediaPlayer = new MediaPlayer[1];        videoView.start();        videoView.setOnInfoListener(new MediaPlayer.OnInfoListener() {            @Override            public boolean onInfo(MediaPlayer mp, int what, int extra) {                mediaPlayer[0] = mp;                mp.setLooping(true);                imgThumb.animate().alpha(0).setDuration(200).start();                return false;            }        });        videoView.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {            @Override            public void onPrepared(MediaPlayer mp) {
            }        });

        imgPlay.setOnClickListener(new View.OnClickListener() {            boolean isPlaying = true;
            @Override            public void onClick(View v) {                if (videoView.isPlaying()) {                    imgPlay.animate().alpha(1f).start();                    videoView.pause();                    isPlaying = false;                } else {                    imgPlay.animate().alpha(0f).start();                    videoView.start();                    isPlaying = true;                }            }        });    }

监听每个Item的移出和移进

自定义LinearLayoutManager，并实现：

RecyclerView.OnChildAttachStateChangeListener

接口。

OnChildAttachStateChangeListener接口源码如下：

    public interface OnChildAttachStateChangeListener {
        /**         * Called when a view is attached to the RecyclerView.         *         * @param view The View which is attached to the RecyclerView         */        void onChildViewAttachedToWindow(@NonNull View view);
        /**         * Called when a view is detached from RecyclerView.         *         * @param view The View which is being detached from the RecyclerView         */        void onChildViewDetachedFromWindow(@NonNull View view);    }

onChildViewAttachedToWindow方法
是将Item添加进来的时候调用；
onChildViewDetachedFromWindow方法
是将Item移除出去的时候调用。

需要在onAttachedToWindow方法中调用

addOnChildAttachStateChangeListener方法。

scrollVerticallyBy方法中实时获取垂直滑动的距离值；

自定义的MyLayoutManager代码如下：

public class MyLayoutManager extends LinearLayoutManager implements RecyclerView.OnChildAttachStateChangeListener {
    //根据这个参数来判断当前是上滑  还是下滑    private int mDrift;    //传进来的监听接口类    private OnViewPagerListener onViewPagerListener;
    public MyLayoutManager(Context context) {        super(context);    }
    public MyLayoutManager(Context context, int orientation, boolean reverseLayout) {        super(context, orientation, reverseLayout);    }
    /**     * 当MyLayoutManager完全放入到RecyclerView中的时候会被调用     */    @Override    public void onAttachedToWindow(RecyclerView view) {        view.addOnChildAttachStateChangeListener(this);        super.onAttachedToWindow(view);    }
    @Override    public int scrollVerticallyBy(int dy, RecyclerView.Recycler recycler, RecyclerView.State state) {        mDrift = dy;        return super.scrollVerticallyBy(dy, recycler, state);    }
    @Override    public boolean canScrollVertically() {        return true;    }
    /**     * 将Item添加进来的时候  调用这个方法     */    @Override    public void onChildViewAttachedToWindow(@NonNull View view) {        if(mDrift >0){            //向上滑            if(onViewPagerListener !=null){                //如果是向上滑动的时候  就选中当前itemView下一个item                onViewPagerListener.onPageSelected(view);            }        }else{            //向下滑            if(onViewPagerListener !=null){                //如果是向上滑动的时候  就选中当前itemView下一个item                onViewPagerListener.onPageSelected(view);            }        }    }
    /**     * 将Item移除出去的时候  调用这个方法     */    @Override    public void onChildViewDetachedFromWindow(@NonNull View view) {        Log.e("EEEEEEEEE","22222222222222222");        if(mDrift >=0){            //向上滑            if(onViewPagerListener !=null){                onViewPagerListener.onPageRelease(view);            }        }else{            //向下滑            if(onViewPagerListener !=null){                onViewPagerListener.onPageRelease(view);            }        }    }
    public void setOnViewPagerListener(OnViewPagerListener onViewPagerListener) {        this.onViewPagerListener = onViewPagerListener;    }}

在Activity中初始化接口，releaseVideo方法表示停止播放视频，playVideo方法表示开始播放视频。

    private void initListener() {        myLayoutManager.setOnViewPagerListener(new OnViewPagerListener() {            @Override            public void onPageRelease(View itemView) {                releaseVideo(itemView);            }
            @Override            public void onPageSelected(View itemView) {                playVideo(itemView);            }        });    }

吸低和吸顶

使用PagerSnapHelper，如下：

 //解决吸顶或者洗低的对象    private PagerSnapHelper pagerSnapHelper;
    public MyLayoutManager(Context context, int orientation, boolean reverseLayout) {        super(context, orientation, reverseLayout);        pagerSnapHelper = new PagerSnapHelper();    }

    /**     * 当MyLayoutManager完全放入到RecyclerView中的时候会被调用     */    @Override    public void onAttachedToWindow(RecyclerView view) {        view.addOnChildAttachStateChangeListener(this);        pagerSnapHelper.attachToRecyclerView(view);        super.onAttachedToWindow(view);    }

  myLayoutManager = new MyLayoutManager(this, OrientationHelper.VERTICAL, false);

解决滑动后播放问题，当滑动停止后播放视频

    /**     * 监听滑动的状态     */    @Override    public void onScrollStateChanged(int state) {        switch (state) {            case RecyclerView.SCROLL_STATE_IDLE:                //现在拿到的就是当前显示的这个item                View snapView = pagerSnapHelper.findSnapView(this);                assert snapView != null;                if (onViewPagerListener != null) {                    onViewPagerListener.onPageSelected(snapView);                }                break;        }        super.onScrollStateChanged(state);    }

源码地址：

https://github.com/345166018/AndroidUI/tree/master/HxDouYin

到这里就完成啦.

点击这里留言交流哦

Android使用RecyclerView实现抖音主界面

实现视频的播放和停止播放

监听每个Item的移出和移进

吸低和吸顶