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Android使用RecycleView来实现数据的上下拖动效果

seven_ • • Android • 阅读 189

导读：本篇文章讲解 Android使用RecycleView来实现数据的上下拖动效果，希望对大家有帮助，欢迎收藏，转发！站点地址：www.bmabk.com

首先先上效果图

Android使用RecycleView来实现数据的上下拖动效果Android使用RecycleView来实现数据的上下拖动效果

1.在moudle中的build引用

implementation 'androidx.recyclerview:recyclerview:1.2.0-alpha06'

2.创建列表的adapter

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {

    private List<Subject> datas;
    private Context mContext;
    private LayoutInflater mLiLayoutInflater;

    public MyAdapter(List<Subject> datas, Context context) {
        this.datas = datas;
        this.mContext = context;
        this.mLiLayoutInflater = LayoutInflater.from(mContext);
    }


    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        return new ViewHolder(mLiLayoutInflater.inflate(R.layout.item_tuodong, parent, false));
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        holder.tv_title.setText(datas.get(position).getTitle());
        holder.img.setImageResource(datas.get(position).getImg());
    }

    @Override
    public int getItemCount() {
        return datas == null ? 0 : datas.size();
    }

    public class ViewHolder extends RecyclerView.ViewHolder {
        TextView tv_title;
        ImageView img;
        LinearLayout ll_item;

        public ViewHolder(View itemView) {
            super(itemView);
            tv_title = itemView.findViewById(R.id.tv_title);
            img =itemView.findViewById(R.id.img);
            ll_item = itemView.findViewById(R.id.ll_item);
        }
    }
}

3.重点就是创建拖拽的lisilistener

public abstract class OnRecyclerItemClickListener implements RecyclerView.OnItemTouchListener {
    private GestureDetectorCompat mGestureDetector;
    private RecyclerView recyclerView;

    public OnRecyclerItemClickListener(RecyclerView recyclerView) {
        this.recyclerView = recyclerView;
        mGestureDetector = new GestureDetectorCompat(recyclerView.getContext(), new ItemTouchHelperGestureListener());
    }

    @Override
    public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) {
        mGestureDetector.onTouchEvent(e);
        return false;
    }

    @Override
    public void onTouchEvent(RecyclerView rv, MotionEvent e) {
        mGestureDetector.onTouchEvent(e);
    }

    @Override
    public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {
    }

    private class ItemTouchHelperGestureListener extends GestureDetector.SimpleOnGestureListener {
        @Override
        public boolean onSingleTapUp(MotionEvent e) {
            View child = recyclerView.findChildViewUnder(e.getX(), e.getY());
            if (child != null) {
                RecyclerView.ViewHolder vh = recyclerView.getChildViewHolder(child);
                onItemClick(vh);
            }
            return true;
        }

        @Override
        public void onLongPress(MotionEvent e) {
            View child = recyclerView.findChildViewUnder(e.getX(), e.getY());
            if (child != null) {
                RecyclerView.ViewHolder vh = recyclerView.getChildViewHolder(child);
                onItemLongClick(vh);
            }
        }
    }

    public abstract void onItemClick(RecyclerView.ViewHolder vh);

    public abstract void onItemLongClick(RecyclerView.ViewHolder vh);
}

4.activity_main.xml 

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recyclerView"
       . android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
        tools:listitem="@layout/item_tuodong"
        tools:itemCount="8"/>

</RelativeLayout>

5.重点拖动的功能实现 Activity

public class MainRecycleViewActivity extends AppCompatActivity {

    private Context mContext;
    private RecyclerView mRecyclerView;

    private String[] titles = {"美食", "电影", "酒店住宿", "休闲娱乐", "外卖", "自助餐", "KTV", "机票/火车票", "周边游", "美甲美睫",
            "火锅", "生日蛋糕", "甜品饮品", "水上乐园", "汽车服务", "美发", "丽人", "景点", "足疗按摩", "运动健身", "健身", "超市", "买菜",
            "今日新单", "小吃快餐", "面膜", "洗浴/汗蒸", "母婴亲子", "生活服务", "婚纱摄影", "学习培训", "家装", "结婚", "全部分配"};
    private List<Subject> datas = new ArrayList<>();
    private ItemTouchHelper mItemTouchHelper;
    private MyAdapter myAdapter;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mContext = this;
        initDate();
        initView();

    }

    public void initDate() {
        //初始化data
        for (int i = 0; i < titles.length; i++) {
            datas.add(new Subject(titles[i], R.mipmap.ic_category));
        }
    }

    public void initView() {
        mRecyclerView = findViewById(R.id.recyclerView);
        myAdapter = new MyAdapter(datas, mContext);
        mRecyclerView.setAdapter(myAdapter);

        mRecyclerView.addOnItemTouchListener(new OnRecyclerItemClickListener(mRecyclerView) {
            @Override
            public void onItemClick(RecyclerView.ViewHolder vh) {
                Toast.makeText(mContext, datas.get(vh.getLayoutPosition()).getTitle(), Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onItemLongClick(RecyclerView.ViewHolder vh) {
                //判断被拖拽的是否是前两个，如果不是则执行拖拽
//                if (vh.getLayoutPosition() != 0 && vh.getLayoutPosition() != 1) {
                if (vh.getLayoutPosition() != 0) {
                    mItemTouchHelper.startDrag(vh);
                    //获取系统震动服务
//                    Vibrator vib = (Vibrator) getSystemService(Service.VIBRATOR_SERVICE);//震动70毫秒
//                    vib.vibrate(70);

                }
            }
        });

        mItemTouchHelper = new ItemTouchHelper(new ItemTouchHelper.Callback() {

            /**
             * 是否处理滑动事件 以及拖拽和滑动的方向 如果是列表类型的RecyclerView的只存在UP和DOWN，
             * 如果是网格类RecyclerView则还应该多有LEFT和RIGHT
             * @param recyclerView
             * @param viewHolder
             * @return
             */
            @Override
            public int getMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
                if (recyclerView.getLayoutManager() instanceof GridLayoutManager) {
                    final int dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN |
                            ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT;
                    final int swipeFlags = 0;
                    return makeMovementFlags(dragFlags, swipeFlags);
                } else {
                    final int dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN;
                    final int swipeFlags = 0;
//                    final int swipeFlags = ItemTouchHelper.START | ItemTouchHelper.END;
                    return makeMovementFlags(dragFlags, swipeFlags);
                }
            }

            @Override
            public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
                //得到当拖拽的viewHolder的Position
                int fromPosition = viewHolder.getAdapterPosition();
                //拿到当前拖拽到的item的viewHolder
                int toPosition = target.getAdapterPosition();
                if (fromPosition < toPosition) {
                    for (int i = fromPosition; i < toPosition; i++) {
                        Collections.swap(datas, i, i + 1);
                    }
                } else {
                    for (int i = fromPosition; i > toPosition; i--) {
                        Collections.swap(datas, i, i - 1);
                    }
                }
                myAdapter.notifyItemMoved(fromPosition, toPosition);
                return true;
            }

            @Override
            public void onSwiped(RecyclerView.ViewHolder viewHolder, int direction) {
//                int position = viewHolder.getAdapterPosition();
//                myAdapter.notifyItemRemoved(position);
//                datas.remove(position);
            }

            /**
             * 重写拖拽可用
             * @return
             */
            @Override
            public boolean isLongPressDragEnabled() {
                return false;
            }

            /**
             * 长按选中Item的时候开始调用
             *
             * @param viewHolder
             * @param actionState
             */
            @Override
            public void onSelectedChanged(RecyclerView.ViewHolder viewHolder, int actionState) {
                if (actionState != ItemTouchHelper.ACTION_STATE_IDLE) {
                    viewHolder.itemView.setBackgroundColor(Color.LTGRAY);
                }
                super.onSelectedChanged(viewHolder, actionState);
            }

            /**
             * 手指松开的时候还原
             * @param recyclerView
             * @param viewHolder
             */
            @Override
            public void clearView(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
                super.clearView(recyclerView, viewHolder);
                viewHolder.itemView.setBackgroundColor(0);
                for (int i = 0; i < datas.size(); i++) {
                    Log.e("======" ,"name = "+datas.get(i).getTitle());
                }
            }
        });

        mItemTouchHelper.attachToRecyclerView(mRecyclerView);

    }


}

到此就结束了，demo下载地址：https://download.csdn.net/download/yyxhzdm/15435538

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Android使用RecycleView来实现数据的上下拖动效果

 

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