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>