Android 在RecyclerView ItemTouchHelper中隐藏一小行

我是Android studio的新手。我使用数据列表创建了一个RecyclerView，并使用ItemTouchHelper在Swipped上实现了该事件。当我从右向左滑动一个孩子时，我看到一条像照片中那样的小线条

我会把这条小线藏起来。RecyclerView可以是什么属性或元素

下面是活动的xml文件

<?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"
    android:backgroundTint="?android:attr/colorBackground"
    tools:context=".TrippyList">

    <LinearLayout
        android:id="@+id/linearLayout13"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <TextView
            android:id="@+id/trippyListWelcome"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:layout_marginStart="8dp"
            android:layout_marginTop="8dp"
            android:layout_marginEnd="8dp"
            android:text="@string/nameLabel"
            android:textColor="?attr/colorPrimary"
            android:textSize="24sp"
            android:textStyle="bold" />

        <TextView
            android:id="@+id/textView4"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:layout_marginStart="8dp"
            android:layout_marginTop="4dp"
            android:layout_marginEnd="8dp"
            android:text="@string/trippyWelcome2"
            android:textColor="?attr/colorPrimary"
            android:textSize="24sp"
            android:textStyle="bold" />

        <View
            android:id="@+id/view2"
            android:layout_width="300dp"
            android:layout_height="2dp"
            android:layout_gravity="center"
            android:layout_marginTop="16dp"
            android:background="#c0c0c0"
            android:backgroundTint="?attr/colorPrimary"
            android:visibility="visible"
            app:layout_constraintWidth_percent="0.7" />
    </LinearLayout>

    <LinearLayout
        android:id="@+id/linearLayout12"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginBottom="8dp"
        android:orientation="horizontal"
        app:layout_constraintBottom_toTopOf="@+id/linearLayout9"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent">

        <com.google.android.gms.ads.AdView
            android:id="@+id/banner_trippylist"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="16dp"
            android:layout_marginTop="8dp"
            android:layout_marginEnd="16dp"
            android:layout_weight="1"
            app:adSize="BANNER"
            app:adUnitId="ca-app-pub-3940256099942544/6300978111" />

        <com.google.android.material.floatingactionbutton.FloatingActionButton
            android:id="@+id/trippyList_addbtn"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="8dp"
            android:layout_marginRight="16dp"
            android:layout_marginBottom="8dp"
            android:clickable="true"
            android:src="@drawable/plus"
            tools:srcCompat="@android:drawable/ic_menu_add" />

    </LinearLayout>

    <LinearLayout
        android:id="@+id/linearLayout9"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.341"
        app:layout_constraintStart_toStartOf="parent">

        <com.google.android.material.bottomnavigation.BottomNavigationView
            android:id="@+id/navigation_bar_trippy_modify"
            android:layout_width="match_parent"
            android:layout_height="61dp"
            android:elevation="4dp"
            android:foregroundTint="?attr/colorAccent"
            android:longClickable="false"
            app:elevation="4dp"
            app:itemIconSize="@dimen/trippy_navbar_size"
            app:itemIconTint="?attr/colorAccent"
            app:itemTextColor="?attr/colorAccent"
            app:menu="@menu/menu" />

    </LinearLayout>

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/lista_trippy"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:cacheColorHint="#00000000"
        android:background="#00000000"
        android:isScrollContainer="false"
        android:keepScreenOn="false"
        android:nestedScrollingEnabled="false"
        android:overScrollMode="always"
        android:requiresFadingEdge="none"
        android:scrollIndicators="none"
        android:scrollbarAlwaysDrawVerticalTrack="false"
        android:scrollbars="vertical"
        android:splitMotionEvents="true"
        android:verticalScrollbarPosition="defaultPosition"
        app:layout_constraintBottom_toTopOf="@+id/linearLayout12"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/linearLayout13"
        app:layout_constraintVertical_bias="0.0" />

</androidx.constraintlayout.widget.ConstraintLayout>

深入了解ItemTouchHelper实现

   ItemTouchHelper touchHelper = new ItemTouchHelper(new ItemTouchHelper.SimpleCallback(ItemTouchHelper.START, ItemTouchHelper.RIGHT | ItemTouchHelper.LEFT) {

                @Override
                public boolean onMove(@NonNull RecyclerView recyclerView, @NonNull RecyclerView.ViewHolder viewHolder, @NonNull RecyclerView.ViewHolder target) {
                    return false;
                }


                @Override
                public void onChildDraw(Canvas c, RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, boolean isCurrentlyActive) {
                    super.onChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive);

                    ColorDrawable background = null;
                    Drawable icon = null;

                    if (dX > 0) {
                        background = new ColorDrawable(Color.RED);
                        icon = ContextCompat.getDrawable(getApplicationContext(), R.drawable.bin);
                    } else {
                        background = new ColorDrawable(Color.BLUE);
                        switch (scelta) {
                            case "1": //delete
                                icon = ContextCompat.getDrawable(getApplicationContext(), R.drawable.bin);
                                break;
                            case "2": // Modifica
                                icon = ContextCompat.getDrawable(getApplicationContext(), R.drawable.modify);
                                break;
                            case "3": // Condividi
                                icon = ContextCompat.getDrawable(getApplicationContext(), R.drawable.share);
                                break;
                            default:
                                icon = ContextCompat.getDrawable(getApplicationContext(), R.drawable.bin);
                                break;
                        }


                    }

                    int iconMargin = (viewHolder.itemView.getHeight() - icon.getIntrinsicHeight()) / 2;
                    int iconTop = viewHolder.itemView.getTop() + (viewHolder.itemView.getHeight() - icon.getIntrinsicHeight()) / 2;
                    int iconBottom = iconTop + icon.getIntrinsicHeight();
                    View itemView = viewHolder.itemView;
                    if (dX > 0) { // Swiping to the right
                        int iconLeft = itemView.getLeft() + iconMargin;
                        int iconRight = itemView.getLeft() + iconMargin + icon.getIntrinsicWidth();
                        icon.setBounds(iconLeft, iconTop, iconRight, iconBottom);

                        background.setBounds(itemView.getLeft(), itemView.getTop(),
                                itemView.getLeft() + ((int) dX),
                                itemView.getBottom());
                    } else if (dX < 0) { // Swiping to the left
                        int iconLeft = itemView.getRight() - iconMargin - icon.getIntrinsicWidth();
                        int iconRight = itemView.getRight() - iconMargin;
                        icon.setBounds(iconLeft, iconTop, iconRight, iconBottom);

                        background.setBounds(itemView.getRight() + ((int) dX),
                                itemView.getTop(), itemView.getRight(), itemView.getBottom());
                    } else { // view is unSwiped
                        background.setBounds(0, 0, 0, 0);
                    }

                    background.draw(c);
                    icon.draw(c);
                }

                @Override
                public void onSwiped(@NonNull RecyclerView.ViewHolder viewHolder, int direction) {
                    AlertDialog.Builder builder = new AlertDialog.Builder(TrippyList.this);
                    builder.setCancelable(true);

                    if (direction == 4) {

                        switch (scelta) {
                            case "1": //delete
                                eleminaElemento(builder, viewHolder);
                                break;
                            case "2": // Modifica
                                curtrip = getTrippyDet(viewHolder);
                                Intent toTrippyMod = new Intent(getApplicationContext(), TrippyModify.class);
                                toTrippyMod.putExtra("currentTrip", curtrip);
                                toTrippyMod.putExtra("currentUser", current);
                                startActivity(toTrippyMod);
                                myAdapter.notifyItemChanged(viewHolder.getAdapterPosition());
                                break;
                            case "3": // Condividi
                                FragmentManager fm = getSupportFragmentManager();
                                ShareTrippyFragment stf = new ShareTrippyFragment(trippies.get(viewHolder.getAdapterPosition()), true);
                                stf.show(fm, "share_trippy_fragment");
                                myAdapter.notifyItemChanged(viewHolder.getAdapterPosition());

                                break;
                            default:
                                eleminaElemento(builder, viewHolder);
                                break;
                        }

                    } else {
                        eleminaElemento(builder, viewHolder);
                    }

                }
            });
            touchHelper.attachToRecyclerView(trippyList);

ItemTouchHelper touchHelper=new ItemTouchHelper（new ItemTouchHelper.SimpleCallback（ItemTouchHelper.START，ItemTouchHelper.RIGHT | ItemTouchHelper.LEFT）{
@凌驾
公共布尔onMove（@NonNull RecyclerView RecyclerView，@NonNull RecyclerView.ViewHolder ViewHolder，@NonNull RecyclerView.ViewHolder target）{
返回false；
}
@凌驾
public void onChildraw（画布c、RecyclerView RecyclerView、RecyclerView.ViewHolder ViewHolder、float dX、float dY、int actionState、boolean isCurrentlyActive）{
super.onchildraw（c、recyclerView、viewHolder、dX、dY、actionState、isCurrentlyActive）；
彩色可绘制背景=空；
可绘制图标=空；
如果（dX>0）{
背景=新的可着色（颜色为红色）；
icon=ContextCompat.getDrawable（getApplicationContext（），R.drawable.bin）；
}否则{
背景=新的可着色（颜色为蓝色）；
开关（scelta）{
案例“1”：//删除
icon=ContextCompat.getDrawable（getApplicationContext（），R.drawable.bin）；
打破
案例“2”：//修改
icon=ContextCompat.getDrawable（getApplicationContext（），R.drawable.modify）；
打破
案例“3”：//康迪维迪
icon=ContextCompat.getDrawable（getApplicationContext（），R.drawable.share）；
打破
违约：
icon=ContextCompat.getDrawable（getApplicationContext（），R.drawable.bin）；
打破
}
}
int iconMargin=（viewHolder.itemView.getHeight（）-icon.getIntrinsicHeight（））/2；
int iconTop=viewHolder.itemView.getTop（）+（viewHolder.itemView.getHeight（）-icon.getIntrinsicHeight（））/2；
int iconBottom=iconTop+icon.getIntrinsicHeight（）；
View itemView=viewHolder.itemView；
如果（dX>0）{//向右滑动
int iconLeft=itemView.getLeft（）+iconMargin；
int iconRight=itemView.getLeft（）+iconMargin+icon.getIntrinsicWidth（）；
icon.setBounds（iconLeft、iconTop、iconRight、iconBottom）；
background.setBounds（itemView.getLeft（），itemView.getTop（），
itemView.getLeft（）+（（int）dX），
getBottom（））；
}如果（dX<0）{//向左滑动，则为else
int iconLeft=itemView.getRight（）-iconMargin-icon.getIntrinsicWidth（）；
int iconRight=itemView.getRight（）-iconMargin；
icon.setBounds（iconLeft、iconTop、iconRight、iconBottom）；
background.setBounds（itemView.getRight（）+（（int）dX），
itemView.getTop（）、itemView.getRight（）、itemView.getBottom（））；
}否则{//视图将不被擦除
背景.背景（0,0,0,0）；
}
背景图（c）；
图标绘制（c）；
}
@凌驾
公共void onsweed（@NonNull RecyclerView.ViewHolder ViewHolder，int-direction）{
AlertDialog.Builder=新建AlertDialog.Builder（TrippyList.this）；
builder.setCancelable（true）；
如果（方向==4）{
开关（scelta）{
案例“1”：//删除
eleminaElemento（建筑商、视图持有者）；
打破
案例“2”：//修改
curtrip=getTrippyDet（viewHolder）；
Intent-toTrippyMod=新的Intent（getApplicationContext（），TrippyModify.class）；
toTrippyMod.putExtra（“当前行程”，curtrip）；
toTrippyMod.putExtra（“当前用户”，当前）；
startActivity（toTrippyMod）；
myAdapter.notifyItemChanged（viewHolder.getAdapterPosition（））；
打破
案例“3”：//康迪维迪
FragmentManager fm=getSupportFragmentManager（）；
ShareTrippyFragment stf=新的ShareTrippyFragment（trippies.get（viewHolder.getAdapterPosition（）），true）；
stf.show（fm，“共享碎片”）；
myAdapter.notifyItemChanged（viewHolder.getAdapterPosition（））；
打破
违约：
eleminaElemento（建筑商、视图持有者）；
打破
}
}否则{
eleminaElemento（建筑商、视图持有者）；
}
    <?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="wrap_content"
    android:alwaysDrawnWithCache="true"
    android:animateLayoutChanges="false">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="horizontal"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <ImageView
            android:id="@+id/trippy_row_icon"
            android:layout_width="59dp"
            android:layout_height="57dp"
            android:layout_marginStart="36dp"
            android:layout_marginTop="16dp"
            app:srcCompat="@drawable/place_placeholder" />

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical">

            <TextView
                android:id="@+id/trippy_row_city"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginStart="100dp"
                android:layout_marginTop="16dp"
                android:text="@string/trippyNew_city"
                android:textColor="?attr/colorPrimary"
                android:textSize="18sp"
                android:textStyle="bold" />

            <TextView
                android:id="@+id/trippy_row_dates"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginStart="56dp"
                android:layout_marginTop="12dp"
                android:text="@string/trippyNew_da" />
        </LinearLayout>
    </LinearLayout>

</androidx.constraintlayout.widget.ConstraintLayout>

  package com.trippy.trippy.ListAdapters;

import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import com.trippy.trippy.Entities.Utente;
import com.trippy.trippy.Entities.Viaggio;
import com.trippy.trippy.R;
import com.trippy.trippy.ActivityModify;
import com.trippy.trippy.TrippyList;
import com.trippy.trippy.TrippyRiepilogo;

import java.text.SimpleDateFormat;
import java.util.ArrayList;

public class TrippyListAdapter extends RecyclerView.Adapter<TrippyListAdapter.MyViewHolder> {

    private ArrayList<Viaggio> mDataset;
    private Context context;
    private Utente curUser;

    public static class MyViewHolder extends RecyclerView.ViewHolder {
        public View view;
        public MyViewHolder(View v) {
            super(v);
            view = v;
        }
    }

    public TrippyListAdapter(ArrayList<Viaggio> myDataset, Context context) {
        mDataset = myDataset;
        this.context = context;
    }

    @NonNull
    @Override
    public TrippyListAdapter.MyViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
        // create a new view
        View v =  LayoutInflater.from(viewGroup.getContext())
                .inflate(R.layout.trippy_list_row, viewGroup, false);

        Intent intent = ((Activity) context).getIntent();
        curUser = intent.getExtras().getParcelable("currentUser");

        MyViewHolder vh = new MyViewHolder(v);
        return vh;
    }

    @Override
    public void onBindViewHolder(@NonNull MyViewHolder holder, int position) {

        TextView city = holder.view.findViewById(R.id.trippy_row_city);
        TextView date = holder.view.findViewById(R.id.trippy_row_dates);

        Viaggio curTrip = mDataset.get(position);

        city.setText(curTrip.getLuogo());

        SimpleDateFormat format = new SimpleDateFormat("dd/MM/yyyy");

        date.setText(context.getText(R.string.trippy_dal) + " " + format.format(curTrip.getDaData()) + " " + context.getText(R.string.trippy_al) + " " + format.format(curTrip.getaData()));

        holder.view.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                long now = System.currentTimeMillis();
                if(now - TrippyList.canIClick >= 1000) {
                    TrippyList.canIClick = System.currentTimeMillis();
                    Intent intent = new Intent(context, TrippyRiepilogo.class);
                    intent.putExtra("currentTrip", curTrip);
                    intent.putExtra("currentUser", curUser);
                    context.startActivity(intent);
                }
            }
        });
    }


    @Override
    public int getItemCount() {
        return mDataset.size();
    }

}