Android的RecyclerView实现列表拖动（移动顺序）交换数据位置

先看效果图
这是拖动前的图片

这是拖动列表改变位置后的图片

这里放上视频演示

主活动MainActivity2类代码如下

import Androidx.appcompat.app.AppCompatActivity;import androidx.recyclerview.widget.ItemTouchHelper;import androidx.recyclerview.widget.LinearLayoutManager;import androidx.recyclerview.widget.RecyclerView;import android.annotation.SuppressLint;import android.os.Bundle;import com.example.myapplication001.R;import java.util.ArrayList;import java.util.Collections;import java.util.List;public class MainActivity2 extends AppCompatActivity {    private HomeAdapter rv_1_homeAdapter;    RecyclerView rv_1;    LinearLayoutManager rv_1_Manager;    ItemTouchHelper mItemTouchHelper;    List<String> titles;    @SuppressLint({"MissingInflatedId", "WrongViewCast"})    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main2);        rv_1=findViewById(R.id.rv_1);        titles = new ArrayList<>();        for (int i = 0; i < 50; i++) {            titles.add("中文"+i);        }        rv_1_homeAdapter = new HomeAdapter(getApplicationContext(),titles);        rv_1_Manager=new LinearLayoutManager(getApplicationContext());        //这里使用垂直滑动        rv_1_Manager.setOrientation(LinearLayoutManager.VERTICAL);        rv_1.setLayoutManager(rv_1_Manager);        rv_1.setAdapter(rv_1_homeAdapter);        //添加拖拽事件         lonGClickPosition：初始索引值            ActionUpPosition：结束索引值        mItemTouchHelper = new ItemTouchHelper(new MyItemTouchHelper(this,titles,rv_1_homeAdapter,(longClickPosition, ActionUpPosition)-> {            if (longClickPosition==-1)return;            //用swap方法可以交换集合中任意两个元素的位置            Collections.swap(titles,longClickPosition,ActionUpPosition);            //列表的适配器            rv_1_homeAdapter.notifyDataSetChanged();        }));        //在这里给列表添加移动顺序        mItemTouchHelper.attachToRecyclerView(rv_1);    }}

主活动MainActivity2类activity_main2的布局代码如下

<?xml version="1.0" encoding="utf-8"?><LinearLayout 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:id="@+id/refreshLa"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical">    <LinearLayout        android:layout_width="match_parent"        android:layout_height="match_parent"        android:orientation="horizontal">        <androidx.recyclerview.widget.RecyclerView            android:id="@+id/rv_1"            android:layout_width="0dp"            android:layout_height="wrap_content"            android:layout_weight="1" />    </LinearLayout></LinearLayout>

适配器HomeAdapter类代码如下

import android.annotation.SuppressLint;import android.content.Context;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.TextView;import androidx.recyclerview.widget.RecyclerView;import com.example.myapplication001.R;import java.util.List;public class HomeAdapter extends RecyclerView.Adapter<HomeAdapter.MyViewHolder>{    private Context mContext;    List<String> list;    public HomeAdapter(Context mContext, List<String> list) {        this.mContext = mContext;        this.list=list;    }        @Override    public MyViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {        MyViewHolder holder = new MyViewHolder(LayoutInflater.from(mContext).inflate(R.layout.item_recycler,viewGroup,false));        return holder;    }        @Override    public void onBindViewHolder(MyViewHolder myViewHolder, @SuppressLint("RecyclerView") int position) {        myViewHolder.tv_name.setText(list.get(position));    }        @Override    public int getItemCount() {        return list.size();    }        class MyViewHolder extends RecyclerView.ViewHolder{        TextView tv_name;        public MyViewHolder(View itemView) {            super(itemView);            tv_name = itemView.findViewById(R.id.tv_name);        }    }}

适配器HomeAdapter类的item_recycler布局代码如下

<?xml version="1.0" encoding="utf-8"?><LinearLayout 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="wrap_content"    android:orientation="vertical">    <LinearLayout        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:orientation="horizontal">        <TextView            android:id="@+id/tv_name"            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:gravity="center"            android:padding="10dp"            android:text="name"            android:textColor="@color/black" />    </LinearLayout>    <View        android:id="@+id/view"        android:layout_width="match_parent"        android:layout_height="1dp"        android:background="#E1DFDF" /></LinearLayout>

MyItemTouchHelper类代码如下

import android.os.Build;import android.util.Log;import androidx.annotation.NonNull;import androidx.annotation.Requiresapi;import androidx.recyclerview.widget.ItemTouchHelper;import androidx.recyclerview.widget.RecyclerView;import java.util.List;public class MyItemTouchHelper extends ItemTouchHelper.Callback{    private List<String> list;    private HomeAdapter recycleViewAdapter;    private RequestDouble<Integer,Integer> mRequestResult;    private int longClickPosition=-1;    MainActivity2 activity;    public MyItemTouchHelper(MainActivity2 activity, List<String> list, HomeAdapter recycleViewAdapter,RequestDouble<Integer,Integer> requestResult) {        Log.d("DDDd","into MyItemTouchHelper");        this.list = list;        this.recycleViewAdapter = recycleViewAdapter;        this.activity = activity;        this.mRequestResult=requestResult;    }    //设置拖拽和item滑动的可支持方向    @Override    public int getMovementFlags(@NonNull RecyclerView recyclerView, @NonNull RecyclerView.ViewHolder viewHolder) {        //这里是设置列表水平拖动     //   final int dragFlags = ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT;  //ItemTouchHelper.UP | ItemTouchHelper.DOWN |        //这里是设置列表是垂直拖动        final int dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN;  //ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT |        //这里是设置网格布局拖动     //   final int dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN | ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT;        final int swipeFlags = 0;        return makeMovementFlags(dragFlags, swipeFlags);    }        @Override    public boolean onMove(@NonNull RecyclerView recyclerView, @NonNull RecyclerView.ViewHolder viewHolder, @NonNull RecyclerView.ViewHolder target) {        // 我们在该方法中实现item数据在数据集合中的位置交换，并调用Adapter的notifyItemMoved完成item界面刷新        recyclerView.getParent().requestDisallowInterceptTouchEvent(true);        //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++) {                //这里暂时注释，用外面的数据来进行交换              //  Collections.swap(list, i, i + 1);            }        } else {            for (int i = fromPosition; i > toPosition; i--) {                //这里暂时注释，用外面的数据来进行交换              //  Collections.swap(list, i, i - 1);            }        }        int movementFlags = getMovementFlags(recyclerView, viewHolder);        Log.d("dddd============="," movementFlags = "+movementFlags);        //通知适配器改变位置        recycleViewAdapter.notifyItemMoved(fromPosition, toPosition);        Log.d("dddd============="," fromPosition = "+fromPosition+" toPosition"+toPosition);        return true;    }        @Override    public void onSwiped(@NonNull RecyclerView.ViewHolder viewHolder, int direction) {    }        @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)    @Override    public void onSelectedChanged(RecyclerView.ViewHolder viewHolder, int actionState) {        //if (actionState != ItemTouchHelper.ACTION_STATE_IDLE) {        //viewHolder.itemView.setBackground(getDrawable(R.drawable.card_drag_selected));        //}        if (viewHolder!=null){            longClickPosition= viewHolder.getAdapterPosition();            Log.d("adapterPosition=====","adapterPosition22222="+longClickPosition);        }        super.onSelectedChanged(viewHolder, actionState);    }        @RequiresApi(api = Build.VERSION_CODES.M)    @Override    public void clearView(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {        int adapterPosition = viewHolder.getAdapterPosition();        if (mRequestResult!=null){            //longClickPosition：这是初始索引值            adapterPosition：这是结束索引值            mRequestResult.result(longClickPosition,adapterPosition);        }        Log.d("adapterPosition=====","adapterPosition="+adapterPosition);        super.clearView(recyclerView, viewHolder);        //viewHolder.itemView.setBackground(getDrawable(R.drawable.card));    }        @Override    public boolean isLongPressDragEnabled() {        //开启长按后开始拖拽的效果        return true;    }    public interface RequestDouble<Integer1,Integer2> {        void result(Integer1 integer1,Integer2 integer2);    }}

来源地址：https://blog.csdn.net/qq_36570506/article/details/130446360