RecyclerView实现拖拽排序效果

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   }  }); 

helper.attachToRecyclerView(rv); 

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 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> 

<?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>