RecyclerView拖拽排序；

效果就是这样，RecyclerView列表可拖拽排序，可删除，可添加；

RecyclerView给我们提供了一个手势器：

 ItemTouchHelper helper = new ItemTouchHelper(new ItemTouchHelper.Callback() {
        @Override
        public int getMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
            int dragFrlg = 0;
            if (recyclerView.getLayoutManager() instanceof GridLayoutManager){
                dragFrlg = ItemTouchHelper.UP|ItemTouchHelper.DOWN|ItemTouchHelper.LEFT|ItemTouchHelper.RIGHT;
            }else if(recyclerView.getLayoutManager() instanceof LinearLayoutManager){
                dragFrlg = ItemTouchHelper.UP|ItemTouchHelper.DOWN;
            }
            return makeMovementFlags(dragFrlg,0);
        }

        @Override
        public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
            //滑动事件  下面注释的代码，滑动后数据和条目错乱，被舍弃
//            Collections.swap(datas,viewHolder.getAdapterPosition(),target.getAdapterPosition());
//            ap.notifyItemMoved(viewHolder.getAdapterPosition(),target.getAdapterPosition());

            //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);
                }
            }
            ap.notifyItemMoved(fromPosition, toPosition);
            return true;
        }

        @Override
        public void onSwiped(RecyclerView.ViewHolder viewHolder, int direction) {
              //侧滑删除可以使用；
        }

        @Override
        public boolean isLongPressDragEnabled() {
            return true;
        }
        /**
         * 长按选中Item的时候开始调用
         * 长按高亮
         * @param viewHolder
         * @param actionState
         */
        @Override
        public void onSelectedChanged(RecyclerView.ViewHolder viewHolder, int actionState) {
            if (actionState != ItemTouchHelper.ACTION_STATE_IDLE) {
                viewHolder.itemView.setBackgroundColor(Color.RED);
                //获取系统震动服务//震动70毫秒
                Vibrator vib = (Vibrator) getSystemService(Service.VIBRATOR_SERVICE);
                vib.vibrate(70);
            }
            super.onSelectedChanged(viewHolder, actionState);
        }

        /**
         * 手指松开的时候还原高亮
         * @param recyclerView
         * @param viewHolder
         */
        @Override
        public void clearView(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
            super.clearView(recyclerView, viewHolder);
            viewHolder.itemView.setBackgroundColor(0);
            ap.notifyDataSetChanged();  //完成拖动后刷新适配器，这样拖动后删除就不会错乱
        }
    });

设置给RecyclerView即可：

helper.attachToRecyclerView(rv);

下面是完整的代码和Xml布局文件：

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    private final String TAG = this.getClass().getSimpleName();
    private List<String> d = Arrays.asList(
            "A","B","C","D","E","F","G"
            ,"H","I","J","K","L","M","N"
            ,"O","P","Q","R","S","T"
            ,"U","V","W","X","Y","Z");
    private RecyclerView rv ;
    private Ap<String> ap;
    private List<String> datas;
    private EditText edAdd;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initData();
        rv = findViewById(R.id.rv);
        edAdd =findViewById(R.id.et_add);
        rv.setLayoutManager(new GridLayoutManager(this,3));
//        rv.setLayoutManager(new LinearLayoutManager(this));
        ap = new Ap(this, datas);
        rv.setAdapter(ap);
        helper.attachToRecyclerView(rv);
        findViewById(R.id.tv).setOnClickListener(this);
        findViewById(R.id.tv_add).setOnClickListener(this);
    }

    private void initData() {
        datas = new ArrayList<>();
//        直接用d操作集合会崩溃，Arrays.asList集合不可增删改；详细可以看我的博客
        for (int i = 0; i < d.size(); i++) {
            datas.add(d.get(i));
        }
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()){
            case R.id.tv:
                for (int i = 0; i < datas.size(); i++) {
                    Log.i(TAG, "onClick: ____"+datas.get(i));
                }
                break;
            case R.id.tv_add:
                ap.add(edAdd.getText().toString().trim());
                edAdd.setText(null);
                break;
        }
    }


    class Ap<T> extends RecyclerView.Adapter<Ap.Vh>{
        private Context context;
        public List<T> stringList;
        public Ap(Context context, List<T> stringList) {
            this.context = context;
            this.stringList = stringList;
        }

        @Override
        public Ap.Vh onCreateViewHolder(ViewGroup parent, int viewType) {
            return new Vh(LayoutInflater.from(context).inflate(R.layout.item_rv,null));
        }

        @Override
        public void onBindViewHolder(Ap.Vh holder, final int position) {
         holder.tv.setText(stringList.get(position).toString());
         holder.iv.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View view) {
                 remove(position);
             }
         });
        }

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

        public void add(T item){
          int position = stringList.size();
         stringList.add(item);
         notifyItemInserted(position);
        }

        public void add(int position,T item){
            stringList.add(position,item);
            notifyItemInserted(position);
        }
//        public void remove(T item) {
//            final int position = stringList.indexOf(item);
//            if (-1 == position)
//                return;
//            stringList.remove(item);
//            notifyItemRemoved(position);
//        }

        public void remove(int position) {
            stringList.remove(position);
            notifyItemRemoved(position);
            notifyItemRangeChanged(position,stringList.size());
        }

        class Vh extends RecyclerView.ViewHolder {

            public Vh(View itemView) {
                super(itemView);
                tv = itemView.findViewById(R.id.tv);
                iv = itemView.findViewById(R.id.iv_delete);
            }
            public TextView tv;
            public ImageView iv;
        }
    }





    ItemTouchHelper helper = new ItemTouchHelper(new ItemTouchHelper.Callback() {
        @Override
        public int getMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
            int dragFrlg = 0;
            if (recyclerView.getLayoutManager() instanceof GridLayoutManager){
                dragFrlg = ItemTouchHelper.UP|ItemTouchHelper.DOWN|ItemTouchHelper.LEFT|ItemTouchHelper.RIGHT;
            }else if(recyclerView.getLayoutManager() instanceof LinearLayoutManager){
                dragFrlg = ItemTouchHelper.UP|ItemTouchHelper.DOWN;
            }
            return makeMovementFlags(dragFrlg,0);
        }

        @Override
        public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
            //滑动事件  下面注释的代码，滑动后数据和条目错乱，被舍弃
//            Collections.swap(datas,viewHolder.getAdapterPosition(),target.getAdapterPosition());
//            ap.notifyItemMoved(viewHolder.getAdapterPosition(),target.getAdapterPosition());

            //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);
                }
            }
            ap.notifyItemMoved(fromPosition, toPosition);
            return true;
        }

        @Override
        public void onSwiped(RecyclerView.ViewHolder viewHolder, int direction) {
              //侧滑删除可以使用；
        }

        @Override
        public boolean isLongPressDragEnabled() {
            return true;
        }
        /**
         * 长按选中Item的时候开始调用
         * 长按高亮
         * @param viewHolder
         * @param actionState
         */
        @Override
        public void onSelectedChanged(RecyclerView.ViewHolder viewHolder, int actionState) {
            if (actionState != ItemTouchHelper.ACTION_STATE_IDLE) {
                viewHolder.itemView.setBackgroundColor(Color.RED);
                //获取系统震动服务//震动70毫秒
                Vibrator vib = (Vibrator) getSystemService(Service.VIBRATOR_SERVICE);
                vib.vibrate(70);
            }
            super.onSelectedChanged(viewHolder, actionState);
        }

        /**
         * 手指松开的时候还原高亮
         * @param recyclerView
         * @param viewHolder
         */
        @Override
        public void clearView(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
            super.clearView(recyclerView, viewHolder);
            viewHolder.itemView.setBackgroundColor(0);
            ap.notifyDataSetChanged();  //完成拖动后刷新适配器，这样拖动后删除就不会错乱
        }
    });
}

Xml布局文件：

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

    <LinearLayout
        android:id="@+id/ll"
        android:background="#eeeeee"
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="48dp">
        <TextView
            android:layout_width="0dp"
            android:layout_weight="1"
            android:layout_height="48dp"
            android:id="@+id/tv"
            android:text="查看数据"
            android:textColor="#fff"
            android:textSize="16dp"
            android:gravity="center"
            android:background="@color/colorAccent"
            />
        <EditText
            android:id="@+id/et_add"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"/>
        <TextView
            android:layout_width="0dp"
            android:layout_weight="1"
            android:layout_height="48dp"
            android:id="@+id/tv_add"
            android:text="添加数据"
            android:textColor="#fff"
            android:textSize="16dp"
            android:gravity="center"
            android:background="#fc1"
            />
    </LinearLayout>
    <android.support.v7.widget.RecyclerView
        android:id="@+id/rv"
        android:layout_below="@id/ll"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</RelativeLayout>

RecyclerView的Item：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:background="#f1f1f1"
    android:layout_height="match_parent">
    <RelativeLayout
        android:layout_width="match_parent"
        android:background="#fff"
        android:layout_margin="0.5dp"
        android:layout_height="match_parent">
    <ImageView
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:src="@mipmap/icon"
        android:id="@+id/iv"
        android:layout_marginTop="10dp"
        />
<TextView
    android:id="@+id/tv"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:textSize="16dp"
    android:layout_below="@id/iv"
    android:gravity="center_horizontal"
    android:layout_marginBottom="10dp"
    />
    <ImageView
        android:layout_width="25dp"
        android:layout_height="25dp"
        android:layout_alignParentRight="true"
        android:src="@mipmap/detele"
        android:id="@+id/iv_delete"
        />
    </RelativeLayout>
</RelativeLayout>