Android中RecyclerView实现拖拽的功能_android 实现recyclerview图片拖拽到外部

功能效果图类似于APP的桌面的图标拖动，各位阅读者就不截图了，直接贴代码了。

继承ItemTouchHelper重写方法

private MyAdapter myAdapter ;
private ItemTouchHelper mItemTouchHelper;
 
 
public class MyItemTouchHelper extends ItemTouchHelper.Callback{
 
 
    @Override
    public int getMovementFlags(@NonNull RecyclerView recyclerView, @NonNull 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;
            return makeMovementFlags(dragFlags, swipeFlags);
        }
    }
 
 
 
    @Override
    public boolean onMove(@NonNull RecyclerView recyclerView, @NonNull RecyclerView.ViewHolder viewHolder, @NonNull 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(list, i, i + 1);
            }
        } else {
            for (int i = fromPosition; i > toPosition; i--) {
                Collections.swap(list, i, i - 1);
            }
        }
        myAdapter.notifyItemMoved(fromPosition, toPosition);
        return true;
    }
 
    @Override
    public void onSwiped(@NonNull RecyclerView.ViewHolder viewHolder, int direction) {
 
    }
 
 
    /**
     * 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.GRAY);
        }
        super.onSelectedChanged(viewHolder, actionState);
    }
 
    /**
     * 手指松开的时候还原
     * @param recyclerView
     * @param viewHolder
     */
    @RequiresApi(api = Build.VERSION_CODES.M)
    @Override
    public void clearView(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
        super.clearView(recyclerView, viewHolder);
        viewHolder.itemView.setBackgroundColor(getColor(R.color.black_alpha_01));
    }
 
    /**
     * 重写拖拽不可用
     * @return
     */
    @Override
    public boolean isLongPressDragEnabled() {
        return true;
    }
}

适配器如下

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder>{
        List<MainTabNewBean.ResultdataBean.ListBean> list ;
        public MyAdapter (List<MainTabNewBean.ResultdataBean.ListBean> list){
            this.list = list ;
        }
        @NonNull
        @Override
        public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
            return new MyViewHolder(LayoutInflater.from(NewMainTableActivity.this).inflate(R.layout.item_new_main,parent,false));
        }
 
 
 
        @Override
        public void onBindViewHolder(@NonNull MyViewHolder holder, int position) {
            holder.tvMainText.setText(list.get(position).getSubjectTitle());
            Glide.with(NewMainTableActivity.this).load(list.get(position).getSubjectIcon()).into(holder.ivMainImg);
            holder.tvMainText.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
//                    NewMainTableActivity.this.startActivity(new Intent(MainActivity.this,VideoNomarlActivity.class));
                }
            });
        }
 
        @Override
        public int getItemCount() {
            return list.size();
        }
 
        public class MyViewHolder extends RecyclerView.ViewHolder{
 
            public ImageView ivMainImg ;
            public TextView tvMainText ;
            public LinearLayout llMainItemBac ;
            public MyViewHolder(@NonNull View itemView) {
                super(itemView);
                ivMainImg = itemView.findViewById(R.id.ivMainImg);
                tvMainText = itemView.findViewById(R.id.tvMainText);
                llMainItemBac = itemView.findViewById(R.id.llMainItemBac);
            }
        }
    }

item_new_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@color/black_alpha_01"
    android:baselineAligned="false"
    android:orientation="vertical" >
 
        <LinearLayout
            android:id="@+id/llMainItemBac"
            android:layout_margin="0.5dp"
            android:padding="4dp"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="@color/white_color"
            android:gravity="center">
 
            <RelativeLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:background="@color/clear_color"
                android:gravity="center">
 
                <ImageView
                    android:id="@+id/ivMainImg"
                    android:layout_width="40dip"
                    android:layout_height="40dip"
                    android:layout_centerHorizontal="true"
                    android:scaleType="fitXY"
                    />
 
                <TextView
                    android:id="@+id/tvMainText"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_below="@id/ivMainImg"
                    android:layout_marginLeft="10dip"
                    android:layout_marginRight="10dip"
                    android:layout_marginTop="10dip"
                    android:background="@color/clear_color"
                    android:ellipsize="end"
                    android:gravity="center_vertical|center_horizontal"
                    android:textColor="@color/ua_dark_gray_text_color"
                    android:textSize="16sp"
                    android:text=""/>
            </RelativeLayout>
        </LinearLayout>
 
 
</LinearLayout>

Activity中的实现

MainTabNewBean是根据自己的数据类型生成的，可以根据自己的需求去改

 rv = findViewById(R.id.rc_people_list);
        GridLayoutManager gridLayoutManager=new GridLayoutManager(this,3) ;
        rv.setLayoutManager(gridLayoutManager);
 
 
  MainTabNewBean mainTabNewBean = new Gson().fromJson(s,MainTabNewBean.class);
        list = mainTabNewBean.getResultdata().getList();
        rv.setAdapter(myAdapter = new MyAdapter(list));
        Log.i("ewqeqw", "getDate: "+list.size());
        mItemTouchHelper = new ItemTouchHelper(new MyItemTouchHelper());
        mItemTouchHelper.attachToRecyclerView(rv);