自动轮播的RecyclerView

转载来自 http://m.jb51.net/article/99171.htm

这篇文章主要为大家详细介绍了android RecyclerView打造自动循环效果，非常实用的循环滚动效果,具有一定的参考价值，感兴趣的小伙伴们可以参考一下

先看效果图

主要处理的地方:

1. RecyclerView中Adapter的item个人可以无限轮询.
2. RecyclerView自动滑动
3. 手指按下时滑动停止,手指抬起后继续自动滑动

自定义 RecyclerView

public class AutoPollRecyclerView extends RecyclerView {
    private static final long TIME_AUTO_POLL = 16;
    AutoPollTask autoPollTask;
    private boolean running;  //标示是否正在自动轮询
    private boolean canRun;  //标示是否可以自动轮询,可在不需要的是否置false

    public AutoPollRecyclerView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        autoPollTask = new AutoPollTask(this);
    }

    static class AutoPollTask implements Runnable {
        private final WeakReference<AutoPollRecyclerView> mReference;
        //使用弱引用持有外部类引用->防止内存泄漏
        public AutoPollTask(AutoPollRecyclerView reference) {
            this.mReference = new WeakReference<AutoPollRecyclerView>(reference);
        }
        @Override
        public void run() {
            AutoPollRecyclerView recyclerView = mReference.get();
            if (recyclerView != null && recyclerView.running && recyclerView.canRun) {
                recyclerView.scrollBy(2, 2);
                recyclerView.postDelayed(recyclerView.autoPollTask,recyclerView.TIME_AUTO_POLL);
            }
        }
    }

    //开启:如果正在运行,先停止->再开启
    public void start() {
        if (running)
            stop();
        canRun = true;
        running = true;
        postDelayed(autoPollTask,TIME_AUTO_POLL);
    }
    public void stop(){
        running = false;
        removeCallbacks(autoPollTask);
    }

    @Override
    public boolean onTouchEvent(MotionEvent e) {
        switch (e.getAction()){
            case MotionEvent.ACTION_DOWN:
                if (running)
                    stop();
                break;
            case MotionEvent.ACTION_UP:
            case MotionEvent.ACTION_CANCEL:
            case MotionEvent.ACTION_OUTSIDE:
                if (canRun)
                    start();
                break;
        }
        return super.onTouchEvent(e);
    }
}

Adapter

public class AutoPollAdapter extends RecyclerView.Adapter<AutoPollAdapter.BaseViewHolder> {
    private final Context mContext;
    private final List<String> mData;

    public AutoPollAdapter(Context context, List<String> list) {
        this.mContext = context;
        this.mData = list;
    }
    @Override
    public BaseViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(mContext).inflate(R.layout.viewholder_auto, parent, false);
        BaseViewHolder holder = new BaseViewHolder(view);
        return holder;
    }

    @Override
    public void onBindViewHolder(BaseViewHolder holder, int position) {
        String data = mData.get(position%mData.size());
        holder.setText(R.id.tv_content,data);
    }
    @Override
    public int getItemCount() {
        return Integer.MAX_VALUE;
    }


    class BaseViewHolder extends RecyclerView.ViewHolder{

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

        private void setText(int resLayout,String text){
            TextView tvContent = (TextView) itemView.findViewById(R.id.tv_content);
            tvContent.setText(text);
        }
    }
}

Activity

public class AutoPollActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_auto_poll);

        initView();
    }
    private void initView() {
        AutoPollRecyclerView mRecyclerView = (AutoPollRecyclerView) findViewById(R.id.rv_recycleView);
        List<String> list = new ArrayList<>();
        for (int i = 0; i < 5; ) {
            list.add(" Item: " + ++i);
        }
        AutoPollAdapter adapter = new AutoPollAdapter(this, list);
        mRecyclerView.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false));
        mRecyclerView.addItemDecoration(new DividerItemDecoration(this, DividerItemDecoration.HORIZONTAL));
        mRecyclerView.setAdapter(adapter);
        if (true) //保证itemCount的总个数宽度超过屏幕宽度->自己处理
            mRecyclerView.start();
    }
}