如何使用kotlin滑动删除存储在firestore中的recyclerview项目？

Posted 2023-04-19

【中文标题】如何使用kotlin滑动删除存储在firestore中的recyclerview项目？

【英文标题】：How to swipe delete recyclerview items stored in firestore using kotlin?

【发布时间】：2021-08-25 04:21:25

【问题描述】：

下面是我的 app_bar_main 文件，其中包含一个工具栏和用于创建板的工厂。 这个布局文件包含在 main_content 中，它有一个回收器视图。

app_bar_main

<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout 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_
    android:layout_
    tools:context=".activities.MainActivity">

    <com.google.android.material.appbar.AppBarLayout
        android:layout_
        android:layout_
        android:theme="@style/Theme.Manageio.AppBarOverlay">

        <androidx.appcompat.widget.Toolbar
            android:id="@+id/toolbar_main_activity"
            android:layout_
            android:layout_
            android:background="?attr/colorPrimary"
            app:popupTheme="@style/Theme.Manageio.PopUpOverlay" />
    </com.google.android.material.appbar.AppBarLayout>

    <include layout="@layout/main_content" />

    <com.google.android.material.floatingactionbutton.FloatingActionButton
        android:id="@+id/fab_createBoard"
        android:layout_
        android:layout_
        android:layout_gravity="bottom|end"
        android:layout_margin="24dp"
        app:srcCompat="@drawable/ic_vector_add"
        android:background="@color/primaryColor" />

</androidx.coordinatorlayout.widget.CoordinatorLayout>

ma​​in_content

<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_
    android:layout_
    android:gravity="center"
    android:background="@color/lightPrimaryColor"
    android:orientation="vertical"
    android:padding="16dp"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:context=".activities.MainActivity">


    <androidx.cardview.widget.CardView
        android:layout_
        android:layout_
        android:background="@color/white"
        android:elevation="5dp"
        app:cardCornerRadius="10dp">


        <androidx.recyclerview.widget.RecyclerView
            android:id="@+id/rv_boardList"
            android:layout_
            android:layout_
            app:item_layout="@layout/item_board"
            android:visibility="gone"

            />

        <TextView
            android:layout_
            android:layout_
            android:id="@+id/tv_noBoardsAvailable"
            android:gravity="center"
            android:textSize="32sp"
            android:fontFamily="@font/boogaloo"
            android:textColor="@color/secondaryText"
            android:text="No Boards Available!"/>

    </androidx.cardview.widget.CardView>
</LinearLayout>

现在，每当我点击 fab 时，它都会将我带到 CreateBoardActivity，它会创建板并将其存储在 firestore 中

CreateBoardActivity

import android.Manifest
import android.app.Activity
import android.content.Intent
import android.content.pm.PackageManager
import android.net.Uri
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.util.Log
import android.widget.Toast
import androidx.core.app.ActivityCompat
import androidx.core.content.ContextCompat
import com.bumptech.glide.Glide
import com.example.manageio.R
import com.example.manageio.firebase.FirestoreClass
import com.example.manageio.models.Board
import com.example.manageio.utils.Constants
import com.google.firebase.storage.FirebaseStorage
import com.google.firebase.storage.StorageReference
import kotlinx.android.synthetic.main.activity_create_board.*
import kotlinx.android.synthetic.main.activity_profile.*
import java.io.IOException

class CreateBoardActivity : BaseActivity() 

    private var mSelectedImageFileUri : Uri?= null

    private lateinit var mUserName : String

    private var mBoardImageURL : String = ""

    override fun onCreate(savedInstanceState: Bundle?) 
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_create_board)

        if(intent.hasExtra(Constants.NAME))
            mUserName = intent.getStringExtra(Constants.NAME).toString()
        

        iv_boardImage.setOnClickListener 
            if (ContextCompat.checkSelfPermission(
                    this,
                    Manifest.permission.READ_EXTERNAL_STORAGE
                ) == PackageManager.PERMISSION_GRANTED
            ) 
                Constants.showImageChooser(this)
             else 
                ActivityCompat.requestPermissions(
                    this,
                    arrayOf(Manifest.permission.READ_EXTERNAL_STORAGE),
                    Constants.READ_STORAGE_PERMISSION_CODE
                )
            
        

        createBoard_createBtn.setOnClickListener 
            if(mSelectedImageFileUri!=null)
                uploadBoardImage()
            else
                showProgressDialog(resources.getString(R.string.please_wait))
                createBoard()
            
        
    

    private fun createBoard()
        val assignedUserArrayList : ArrayList<String> = ArrayList()
        assignedUserArrayList.add(getCurrentUserId())

        var board = Board(
            createBoard_et_boardName.text.toString(),
            mBoardImageURL,
            mUserName,
            assignedUserArrayList
        )

        FirestoreClass().createBoard(this,board)
    

    private fun uploadBoardImage()
        showProgressDialog(resources.getString(R.string.please_wait))

        val sRef: StorageReference = FirebaseStorage.getInstance()
            .reference.child(
                "BOARD_IMAGE" + System.currentTimeMillis() + "." +
                        Constants.getFileExtension(this,mSelectedImageFileUri!!)
            )

        sRef.putFile(mSelectedImageFileUri!!).addOnSuccessListener  taskSnapshot ->
            Log.i(
                "FirebaseBoardImageUrl",
                taskSnapshot.metadata!!.reference!!.downloadUrl.toString()
            )
            taskSnapshot.metadata!!.reference!!.downloadUrl.addOnSuccessListener  uri ->
                Log.i("DownloadBoardImageUrl", uri.toString())
                mBoardImageURL = uri.toString()
                createBoard()
            
        .addOnFailureListener  exception ->
            Toast.makeText(this@CreateBoardActivity, exception.message, Toast.LENGTH_LONG).show()
            hideProgressDialog()
        


    

    fun boardCreatedSuccessfully()
        hideProgressDialog()
        setResult(Activity.RESULT_OK)
        finish()
    

    override fun onRequestPermissionsResult(
        requestCode: Int,
        permissions: Array<out String>,
        grantResults: IntArray
    ) 
        super.onRequestPermissionsResult(requestCode, permissions, grantResults)
        if (requestCode == Constants.READ_STORAGE_PERMISSION_CODE) 
            if (grantResults.isNotEmpty() && grantResults[0] == PackageManager.PERMISSION_GRANTED) 
                Constants.showImageChooser(this)
             else 
                Toast.makeText(
                    this,
                    "You denied the permission for storage.You can allow it from settings",
                    Toast.LENGTH_LONG
                ).show()
            
        
    

    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) 
        super.onActivityResult(requestCode, resultCode, data)
        if (resultCode == Activity.RESULT_OK && requestCode == Constants.PICK_IMAGE_REQUEST_CODE && data!!.data != null) 
            mSelectedImageFileUri = data.data
            try 
                Glide
                    .with(this)
                    .load(mSelectedImageFileUri)
                    .centerCrop()
                    .placeholder(R.color.lightPrimaryColor)
                    .into(iv_boardImage)
             catch (e: IOException) 
                e.printStackTrace()
            
        

    

FireStoreClass

import android.app.Activity
import android.util.Log
import android.widget.Toast
import com.example.manageio.activities.*
import com.example.manageio.models.Board
import com.example.manageio.models.User
import com.example.manageio.utils.Constants
import com.google.firebase.auth.FirebaseAuth
import com.google.firebase.firestore.FirebaseFirestore
import com.google.firebase.firestore.SetOptions

class FirestoreClass 
    private val mFireStore = FirebaseFirestore.getInstance()

   
    fun getBoardDetails(activity: TaskListActivity, documentId: String) 
        mFireStore.collection(Constants.BOARDS)
            .document(documentId)
            .get()
            .addOnSuccessListener  document ->
                val board = document.toObject(Board::class.java)!!
                board.documentId = document.id
                activity.boardDetails(board)

            .addOnFailureListener  e ->
                activity.hideProgressDialog()
                Log.e("FirestoreClass", "Error with exception ", e)
            
    

    fun createBoard(activity: CreateBoardActivity, board: Board) 
        mFireStore.collection(Constants.BOARDS)
            .document()
            .set(board, SetOptions.merge())
            .addOnSuccessListener 
                Toast.makeText(activity, "Board Created Successfully", Toast.LENGTH_SHORT).show()
                activity.boardCreatedSuccessfully()
            .addOnFailureListener  e ->
                activity.hideProgressDialog()
                Log.e("FirestoreClass", "Error with exception ", e)
            
    

    fun getBoardsList(activity: MainActivity) 
        mFireStore.collection(Constants.BOARDS)
            .whereArrayContains(Constants.ASSIGNED_TO, getCurrentUserId())
            .get()
            .addOnSuccessListener  document ->
                val boardlist: ArrayList<Board> = ArrayList()
                for (i in document.documents) 
                    val board = i.toObject(Board::class.java)!!
                    board.documentId = i.id
                    boardlist.add(board)
                

                activity.populateBoardsListToUI(boardlist)
            .addOnFailureListener  e ->
                activity.hideProgressDialog()
                Log.e("FireStoreClass", "Error while creating board.", e)
            
    

    
    fun updateUserProfileData(activity: Activity, userHashMap: HashMap<String, Any>) 
        mFireStore.collection(Constants.USERS)
            .document(getCurrentUserId())
            .update(userHashMap)
            .addOnSuccessListener 
                Log.i("FirestoreClass", "Profile Data Updated Successfully")
                Toast.makeText(
                    activity,
                    "You profile has been updated successfully",
                    Toast.LENGTH_SHORT
                ).show()
                when(activity)
                    is MainActivity ->
                        activity.tokenUpdateSuccess()
                    
                    is ProfileActivity ->
                        activity.profileUpdateSuccess()
                    
                

            .addOnFailureListener  e ->
                when(activity)
                    is MainActivity ->
                        activity.hideProgressDialog()
                    
                    is ProfileActivity ->
                        activity.hideProgressDialog()
                    
                
                Log.e("FirestoreClass", "Error while updating profile", e)
                Toast.makeText(activity, "Error while updating profile", Toast.LENGTH_SHORT).show()
            
    

    fun loadUserData(activity: Activity, readBoardsList: Boolean = false) 
        mFireStore.collection(Constants.USERS)
            .document(getCurrentUserId())
            .get()
            .addOnSuccessListener  document ->

                val loggedInUser = document.toObject(User::class.java)!!

                when (activity) 
                    is LoginActivity -> 
                        activity.loginSuccess(loggedInUser)
                    
                    is MainActivity -> 
                        activity.updateNavigationUserDetails(loggedInUser, readBoardsList)
                    
                    is ProfileActivity -> 
                        activity.setUserDataInUi(loggedInUser)
                    
                


            .addOnFailureListener  e ->
                when (activity) 
                    is LoginActivity -> 
                        activity.hideProgressDialog()
                    
                    is MainActivity -> 
                        activity.hideProgressDialog()
                    
                
                Log.e("FirestoreClass", "Error with exception $e")
            
    

    fun getCurrentUserId(): String 
        val currentUser = FirebaseAuth.getInstance().currentUser
        var currentUserId = ""
        if (currentUser != null) 
            currentUserId = currentUser.uid
        

        return currentUserId
    

    

    fun assignMemberToBoard(activity: MembersActivity, board : Board, user : User)
        val assignedToHashmap = HashMap<String,Any>()
        assignedToHashmap[Constants.ASSIGNED_TO] = board.assignedTo
        mFireStore.collection(Constants.BOARDS)
            .document(board.documentId)
            .update(assignedToHashmap)
            .addOnSuccessListener 
                activity.memberAssignSuccess(user)
            .addOnFailureListener  e ->
                activity.hideProgressDialog()
                Log.e("FirestoreClass", "Error while creating board",e)
            
    

主要活动

import android.app.Activity
import android.content.Context
import android.content.Intent
import android.content.SharedPreferences
import android.os.Bundle
import android.util.Log
import android.view.MenuItem
import android.view.View
import androidx.core.view.GravityCompat
import androidx.recyclerview.widget.LinearLayoutManager
import com.bumptech.glide.Glide
import com.example.manageio.R
import com.example.manageio.adapters.BoardItemsAdapter
import com.example.manageio.firebase.FirestoreClass
import com.example.manageio.models.Board
import com.example.manageio.models.User
import com.example.manageio.utils.Constants
import com.google.android.material.navigation.NavigationView
import com.google.firebase.FirebaseApp.getInstance
import com.google.firebase.auth.FirebaseAuth

import com.google.firebase.installations.FirebaseInstallations
import com.google.firebase.messaging.FirebaseMessaging
import com.google.firebase.messaging.FirebaseMessaging.getInstance
import kotlinx.android.synthetic.main.activity_main.*
import kotlinx.android.synthetic.main.app_bar_main.*
import kotlinx.android.synthetic.main.main_content.*
import kotlinx.android.synthetic.main.nav_header_main.*

class MainActivity : BaseActivity(), NavigationView.OnNavigationItemSelectedListener 

    companion object
        const val MY_PROFILE_REQUEST_CODE : Int = 99
        const val CREATE_BOARD_REQUEST_CODE : Int =98
    

    private lateinit var mUserName : String
    private lateinit var mSharedPreferences : SharedPreferences

    override fun onCreate(savedInstanceState: Bundle?) 
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        setUpActionBar()
        nav_view.setNavigationItemSelectedListener(this)

        mSharedPreferences = this.getSharedPreferences(Constants.MANAGEIO_PREFERENCES, Context.MODE_PRIVATE)
        val tokenUpdated = mSharedPreferences.getBoolean(Constants.FCM_TOKEN_UPDATED,false)

        if(tokenUpdated)
            showProgressDialog(resources.getString(R.string.please_wait))
            FirestoreClass().loadUserData(this@MainActivity,true)
        
        else
            FirebaseInstallations.getInstance().getToken(tokenUpdated).addOnSuccessListener(this@MainActivity)
                instanceIdResult ->
                updateFCMTOKEN(instanceIdResult.token)
            
        
        // TODO Check 1
//        FirestoreClass().loadUserData(this , true)

        fab_createBoard.setOnClickListener
            val intent = Intent(this@MainActivity,CreateBoardActivity::class.java)
            intent.putExtra(Constants.NAME,mUserName)
            startActivityForResult(intent, CREATE_BOARD_REQUEST_CODE)

        

    

    fun populateBoardsListToUI(boardsList : ArrayList<Board>)
        hideProgressDialog()

        if(boardsList.size > 0)
            rv_boardList.visibility = View.VISIBLE
            tv_noBoardsAvailable.visibility = View.GONE

            rv_boardList.layoutManager = LinearLayoutManager(this)
            rv_boardList.setHasFixedSize(true)

            val adapter = BoardItemsAdapter(this,boardsList)
            rv_boardList.adapter = adapter

            adapter.setOnClickListener(object :BoardItemsAdapter.OnClickListener
                override fun onClick(position: Int, model: Board) 
                    val intent = Intent(this@MainActivity,TaskListActivity::class.java)
                    intent.putExtra(Constants.DOCUMENT_ID,model.documentId)
                    startActivity(intent)
                
            )

        else
            rv_boardList.visibility = View.GONE
            tv_noBoardsAvailable.visibility = View.VISIBLE
        
    

    private fun setUpActionBar() 
        setSupportActionBar(toolbar_main_activity)
        toolbar_main_activity.setNavigationIcon(R.drawable.ic_nav_menu)
        toolbar_main_activity.setNavigationOnClickListener 
            toggleDrawer()
        
    

    private fun toggleDrawer() 
        if (drawer_layout.isDrawerOpen(GravityCompat.START)) 
            drawer_layout.closeDrawer(GravityCompat.START)
         else 
            drawer_layout.openDrawer(GravityCompat.START)
        
    

    fun updateNavigationUserDetails(user: User, readBoardsList : Boolean)
        hideProgressDialog()
        mUserName = user.name
        Glide
            .with(this)
            .load(user.image)
            .centerCrop()
            .placeholder(R.drawable.ic_nav_user)
            .into(iv_userImage);

        tv_username.text = user.name

        if(readBoardsList)
            showProgressDialog(resources.getString(R.string.please_wait))
            FirestoreClass().getBoardsList(this)
        
    

    override fun onBackPressed() 
        if (drawer_layout.isDrawerOpen(GravityCompat.START)) 
            drawer_layout.closeDrawer(GravityCompat.START)
         else 
            doubleBackToExit()
        
    

    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) 
        super.onActivityResult(requestCode, resultCode, data)
        if(resultCode == Activity.RESULT_OK && requestCode == MY_PROFILE_REQUEST_CODE)
            FirestoreClass().loadUserData(this)
        else if(resultCode == Activity.RESULT_OK && requestCode == CREATE_BOARD_REQUEST_CODE)
            FirestoreClass().getBoardsList(this)
        
        else
            Log.e("MainActivity", "Cancelled")
        
    

    override fun onNavigationItemSelected(item: MenuItem): Boolean 
        when(item.itemId)
            R.id.nav_my_profile -> 
                startActivityForResult(Intent(this@MainActivity,ProfileActivity::class.java),
                    MY_PROFILE_REQUEST_CODE)
            

            R.id.nav_logout -> 
                FirebaseAuth.getInstance().signOut()
                mSharedPreferences.edit().clear().apply()
                val intent = Intent(this,WelcomeActivity::class.java)
                intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP or Intent.FLAG_ACTIVITY_NEW_TASK)
                startActivity(intent)
                finish()

            

        
        drawer_layout.closeDrawer(GravityCompat.START)
        return true
    

    

**BoardItemsAdapter

import android.content.Context
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.recyclerview.widget.RecyclerView
import com.bumptech.glide.Glide
import com.example.manageio.R
import com.example.manageio.firebase.FirestoreClass
import com.example.manageio.models.Board
import com.example.manageio.utils.Constants
import kotlinx.android.synthetic.main.item_board.view.*

open class BoardItemsAdapter(private val context: Context,private var list: ArrayList<Board>) : RecyclerView.Adapter<RecyclerView.ViewHolder>()


    private var onClickListener : OnClickListener ?= null

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder 
        return MyViewHolder(LayoutInflater.from(context).inflate(R.layout.item_board,parent,false))
    

    override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) 
        val model = list[position]
        if(holder is MyViewHolder)
            Glide
                .with(context)
                .load(model.image)
                .centerCrop()
                .placeholder(R.color.lightPrimaryColor)
                .into(holder.itemView.iv_itemBoardImage)

            holder.itemView.tv_name.text = model.name
            holder.itemView.tv_createdBy.text = "Created By: $model.createdBy"

            holder.itemView.setOnClickListener 
                if(onClickListener!=null)
                    onClickListener!!.onClick(position,model)
                
            
        
    

    interface OnClickListener
        fun onClick(position: Int,model : Board)
    

    fun setOnClickListener(onClickListener: OnClickListener)
        this.onClickListener = onClickListener
    


    override fun getItemCount(): Int 
        return list.size
    



    private class MyViewHolder(view : View) : RecyclerView.ViewHolder(view)

板子（模型）

包 com.example.manageio.models

导入 android.os.Parcel 导入android.os.Parcelable

data class Board(
    val name : String = "",
    val image : String = "",
    val createdBy : String = "",
    val assignedTo : ArrayList<String> = ArrayList(),
    var documentId : String = "",
    var taskList : ArrayList<Task> = ArrayList()

) : Parcelable 
    constructor(parcel: Parcel) : this(
        parcel.readString()!!,
        parcel.readString()!!,
        parcel.readString()!!,
        parcel.createStringArrayList()!!,
        parcel.readString()!!,
        parcel.createTypedArrayList(Task.CREATOR)!!
    )


    override fun writeToParcel(parcel: Parcel, flags: Int) = with(parcel)
        parcel.writeString(name)
        parcel.writeString(image)
        parcel.writeString(createdBy)
        parcel.writeStringList(assignedTo)
        parcel.writeString(documentId)
        parcel.writeTypedList(taskList)
    

    override fun describeContents(): Int 
        return 0
    

    companion object CREATOR : Parcelable.Creator<Board> 
        override fun createFromParcel(parcel: Parcel): Board 
            return Board(parcel)
        

        override fun newArray(size: Int): Array<Board?> 
            return arrayOfNulls(size)
        
    

然后创建的板显示在主要活动中 请参考这些图片

Firestore Image

Main activity image

不是我想要的，每当我滑动一个回收站视图列表时，它就应该被删除。 如何实现它以使其也从 Firestore 中删除？

请不要介意其他不重要的功能。其实这是我第一次问所以我把它都贴在那里了

【问题讨论】：

检查文档以从 Firestore 中删除 firebase.google.com/docs/firestore/manage-data/…

如果您遇到问题，最好在发布问题时创建MCVE。您为此问题发布了近 700（七百）行行代码。人们需要解析和尝试在线调试的内容很多。请编辑您的问题并隔离问题，这样可以增加获得帮助的机会。

但是，我认为这篇文章 How to delete a record from Firestore on a RecylerView left/right swipe? 可能会有所帮助。

首先：欢迎来到 ***，我们很高兴你在这里。但我只能为 @AlexMamo 的评论 +1。

我已经简化了我的问题，请查看此***.com/questions/67938465/…

【参考方案1】：

您需要一个 ItemTouchHelper 回调方法才能在 Android Recycler 视图中实现滑动删除。下面是这样的

abstract class SwipeToDeleteCallback internal constructor(internal var mContext: Context) : ItemTouchHelper.Callback() 
private val mClearPaint: Paint
private val mBackground: ColorDrawable
private val backgroundColor: Int
private val deleteDrawable: Drawable?
private val intrinsicWidth: Int
private val intrinsicHeight: Int


init 
    mBackground = ColorDrawable()
    backgroundColor = Color.parseColor("#b80f0a")
    mClearPaint = Paint()
    mClearPaint.xfermode = PorterDuffXfermode(PorterDuff.Mode.CLEAR)
    deleteDrawable = ContextCompat.getDrawable(mContext, R.drawable.ic_delete)
    intrinsicWidth = deleteDrawable!!.intrinsicWidth
    intrinsicHeight = deleteDrawable.intrinsicHeight



override fun getMovementFlags(recyclerView: RecyclerView, viewHolder: RecyclerView.ViewHolder): Int 
    return ItemTouchHelper.Callback.makeMovementFlags(0, ItemTouchHelper.LEFT)


override fun onMove(recyclerView: RecyclerView, viewHolder: RecyclerView.ViewHolder, viewHolder1: RecyclerView.ViewHolder): Boolean 
    return false


override fun onChildDraw(
     c: Canvas, recyclerView: RecyclerView,  viewHolder: RecyclerView.ViewHolder, dX: Float,
    dY: Float,
    actionState: Int,
    isCurrentlyActive: Boolean
) 
    super.onChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive)

    val itemView = viewHolder.itemView
    val itemHeight = itemView.height

    val isCancelled = dX == 0f && !isCurrentlyActive

    if (isCancelled) 
        clearCanvas(
            c,
            itemView.right + dX,
            itemView.top  + 0f,
            itemView.right + 0f,
            itemView.bottom + 0f
        )
        super.onChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive)
        return
    

    mBackground.color = backgroundColor
    mBackground.setBounds(itemView.right + dX.toInt(), itemView.top, itemView.right, itemView.bottom)
    mBackground.draw(c)

    val deleteIconTop = itemView.top + (itemHeight - intrinsicHeight) / 2
    val deleteIconMargin = (itemHeight - intrinsicHeight) / 2
    val deleteIconLeft = itemView.right - deleteIconMargin - intrinsicWidth
    val deleteIconRight = itemView.right - deleteIconMargin
    val deleteIconBottom = deleteIconTop + intrinsicHeight


    deleteDrawable!!.setBounds(deleteIconLeft, deleteIconTop, deleteIconRight, deleteIconBottom)
    deleteDrawable.draw(c)

    super.onChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive)




private fun clearCanvas(c: Canvas, left: Float, top: Float, right: Float, bottom: Float) 
    c.drawRect(left, top, right, bottom, mClearPaint)



override fun getSwipeThreshold(viewHolder: RecyclerView.ViewHolder): Float 
    return 0.7f

那你就可以这样使用了

recyclerView..addOnItemTouchListener(YourItemTouchHere)

实现 onMove 方法。在firestore上删除只是将firestore中对象路径的值设置为FieldValue.delete（），它将被删除