Android RecyclerView实现滑动删除

package com.example.demo;
 
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.ItemTouchHelper;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
 
import android.graphics.Canvas;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.LinearLayout;
import android.widget.TextView;
 
import java.util.ArrayList;
import java.util.List;
 
/**
 * @author Huang xudong
 * @date 2020/7/26
 */
public class MainActivity extends AppCompatActivity {
 private RecyclerView recyclerView;
 
 private List list=new ArrayList();
 
 class MyAdpter extends RecyclerView.Adapter<MyAdpter.ViewHolder>{
 
  class ViewHolder extends RecyclerView.ViewHolder{
   private TextView textView;
   private LinearLayout linearLayout;
 
   public ViewHolder(@NonNull View itemView) {
    super(itemView);
    linearLayout=itemView.findViewById(R.id.ll_main);
    textView=itemView.findViewById(R.id.tv_main);
   }
  }
 
  @NonNull
  @Override
  public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
   View inflate = LayoutInflater.from(getApplicationContext()).inflate(R.layout.item_demo,parent, false);
   return new ViewHolder(inflate);
  }
 
  @Override
  public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
 
  }
 
  @Override
  public int getItemCount() {
   return list.size();
  }
 }
 
 class CallBack extends ItemTouchHelper.Callback{
  @Override
  public int getMovementFlags(@NonNull RecyclerView recyclerView, @NonNull RecyclerView.ViewHolder viewHolder) {
   return makeMovementFlags(0,ItemTouchHelper.LEFT);
  }
 
  @Override
  public boolean onMove(@NonNull RecyclerView recyclerView, @NonNull RecyclerView.ViewHolder viewHolder, @NonNull RecyclerView.ViewHolder target) {
   return false;
  }
 
  @Override
  public void onSwiped(@NonNull RecyclerView.ViewHolder viewHolder, int direction) {
   /**
    * call max distance start onSwiped call
    */
  }
 
  @Override
  public void onChildDraw(@NonNull Canvas c, @NonNull RecyclerView recyclerView, @NonNull RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, boolean isCurrentlyActive) {
 
 
   if (actionState==ItemTouchHelper.ACTION_STATE_SWIPE){
    /**
     * get {@link TextView#getWidth()}
     */
    ViewGroup viewGroup= (ViewGroup) viewHolder.itemView;
    TextView textView = (TextView) viewGroup.getChildAt(1);
    ViewGroup.LayoutParams layoutParams = textView.getLayoutParams();
    if (Math.abs(dX)<=layoutParams.width){
     /**
      * move {@link RecyclerView.ViewHolder} distance
      */
     viewHolder.itemView.scrollTo((int) -dX,0);
     /**
      * callAction or register click bind view
      */
    }
   }
  }
 }
 
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
 
  recyclerView=findViewById(R.id.rv_main);
  list.add(1);
  list.add("2");
  MyAdpter myAdpter=new MyAdpter();
  LinearLayoutManager linearLayoutManager=new LinearLayoutManager(getApplicationContext());
  linearLayoutManager.setOrientation(RecyclerView.VERTICAL);
  recyclerView.setLayoutManager(linearLayoutManager);
  recyclerView.setAdapter(myAdpter);
  ItemTouchHelper itemTouchHelper=new ItemTouchHelper(new CallBack());
  itemTouchHelper.attachToRecyclerView(recyclerView);
 }
}

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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=".MainActivity">
 
 <androidx.recyclerview.widget.RecyclerView
  android:id="@+id/rv_main"
  app:layout_constraintLeft_toLeftOf="parent"
  app:layout_constraintRight_toRightOf="parent"
  app:layout_constraintTop_toTopOf="parent"
  app:layout_constraintBottom_toBottomOf="parent"
  android:layout_width="0dp"
  android:layout_height="0dp">
 
 </androidx.recyclerview.widget.RecyclerView>
 
</androidx.constraintlayout.widget.ConstraintLayout>

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="match_parent"
 android:layout_height="wrap_content"
 android:paddingBottom="10dp"
 xmlns:app="http://schemas.android.com/apk/res-auto">
 
 <LinearLayout
  android:id="@+id/ll_main"
  android:background="@color/colorPrimaryDark"
  app:layout_constraintTop_toTopOf="parent"
  app:layout_constraintLeft_toLeftOf="parent"
  app:layout_constraintRight_toRightOf="parent"
  android:layout_width="0dp"
  android:layout_height="200dp"
  android:orientation="horizontal">
 
 </LinearLayout>
 
 <TextView
  android:textColor="#ffffff"
  android:gravity="center"
  android:id="@+id/tv_main"
  android:textSize="34sp"
  android:text="删 除"
  android:background="@color/colorAccent"
  app:layout_constraintLeft_toRightOf="@id/ll_main"
  app:layout_constraintTop_toTopOf="@id/ll_main"
  app:layout_constraintBottom_toBottomOf="@id/ll_main"
  android:layout_width="180dp"
  android:layout_height="0dp">
 
 </TextView>
 
 
 
</androidx.constraintlayout.widget.ConstraintLayout>