RecyclerView item上下滑动效果

  • LinearLayoutManager效果图:
linear.gif

滑动排序实现的方式,是通过继承ItemTouchHelper.Callback 重写其的方法,而在这些方法中需要通过接口获取:

public interface OnItemMoveListener {

    void onItemMove(int fromPosition, int toPosition);

    void onItemDismiss(int position);
}

So 我实例了以上的接口为了方便在adapter中使用的时候处理我需要做的操作。

接下来直接上ItemTouchHelper.Callback,我分别做了GridLayoutManager和LinearLayoutManager的可拖滑动方向以及侧滑删除判断
public class MoveItem extends ItemTouchHelper.Callback {

    private OnItemMoveListener adapter;//因为要在adaper中使用所以直接赋值此名

    public MoveItem(OnItemMoveListener adapter) {
        this.adapter = adapter;
    }
    @Override
    public int getMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
        //主要设置屏幕中Item可拖动的方向,以及侧滑的方向。
        RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
        if (layoutManager instanceof GridLayoutManager) {
            int dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN | ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT;
            int swipeFlags = ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT;
            return makeMovementFlags(dragFlags, swipeFlags);
        } else if (layoutManager instanceof LinearLayoutManager) {
            LinearLayoutManager linearLayoutManager = (LinearLayoutManager) layoutManager;
            if (linearLayoutManager.getOrientation() == LinearLayoutManager.HORIZONTAL) {
                int dragFlags = ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT;
                int swipeFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN;
                return makeMovementFlags(dragFlags, swipeFlags);
            } else {
                int dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN;
                int swipeFlags = ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT;
                return makeMovementFlags(dragFlags, swipeFlags);
            }
        }
        return makeMovementFlags(0, 0);
    }

    @Override
    public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
        adapter.onItemMove(viewHolder.getAdapterPosition(), target.getAdapterPosition());//移动
        return true;
    }

    @Override
    public void onSwiped(RecyclerView.ViewHolder viewHolder, int direction) {
        adapter.onItemDismiss(viewHolder.getAdapterPosition());//侧滑
    }

    @Override
    public boolean isLongPressDragEnabled() {
        return true;//必须为true才支持
    }

    @Override
    public boolean isItemViewSwipeEnabled() {
        return true;//必须为true才支持
    }
}

接口的方式也是为了进行传值,接下来是adapter中的操作。为adapter实现接口,重写方法

public class RecyclerMoveAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> implements 
OnItemMoveListener {
    private List<String> list;
    private Context mContext;
    private LayoutInflater inflater;

    public RecyclerMoveAdapter(Context mContext) {
        this.mContext = mContext;
        inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }

    public void setData(List<String> list) {
        this.list = list;
        notifyDataSetChanged();
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = inflater.inflate(R.layout.item_recycler_move, parent, false);
        MyViewHolder holder = new MyViewHolder(view);
        return holder;
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
        MyViewHolder myViewHolder = (MyViewHolder) holder;
        myViewHolder.text.setText(list.get(position));
    }

    @Override
    public int getItemCount() {
        return list.size();
    }

    @Override
    public void onItemMove(int fromPosition, int toPosition) {
        Collections.swap(list, fromPosition, toPosition);
        notifyItemMoved(fromPosition, toPosition);
    }

    @Override
    public void onItemDismiss(int position) {
        list.remove(position);
        notifyDataSetChanged();
    }

    class MyViewHolder extends RecyclerView.ViewHolder {
        TextView text;

        public MyViewHolder(View itemView) {
            super(itemView);
            text = (TextView) itemView.findViewById(R.id.text);
        }
    }
}

adapter实现接口,并进行了item顺序的调换以及即时刷新。

使用
    private RecyclerView recycler;
    private List<String> recyclerData = new ArrayList<>();
    private RecyclerMoveAdapter recyclerMoveAdapter;
    private MoveItem moveItem;
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_banner);
        initView();
        initData();
    }
    public void initView() {
        recycler = (RecyclerView) findViewById(R.id.recycler);
        recyclerMoveAdapter = new RecyclerMoveAdapter(this);
        moveItem = new MoveItem(recyclerMoveAdapter);
      
    public void initData() {
       for (int i = 0; i < 20; i++) {
              recyclerData.add(i + "");
        }


      //在itemTouch里面已经进行了布局管理判断。
       //GridLayoutManager layoutManager = new GridLayoutManager(mActivity, 3);
       LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this,LinearLayoutManager.VERTICAL,false);
        recycler.setLayoutManager(linearLayoutManager);
        recycler.setHasFixedSize(true);
        recycler.setAdapter(recyclerMoveAdapter);

        recyclerMoveAdapter.setData(recyclerData);

        ItemTouchHelper helper = new ItemTouchHelper(moveItem);
        helper.attachToRecyclerView(recycler);
    }

csdn,谢谢
https://blog.csdn.net/binbinxiaoz

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