如何从 recyclerView 和 sqlite 数据库中删除 cardview？（科特林 - 安卓）

我正在创建一个带有回收站视图、卡片视图和 SQLite 数据库的应用程序。卡片视图包含标题、描述和删除图标（在项目单击时）。当用户在卡片视图中输入一些数据时，它会显示在回收器视图中并添加到数据库中。

我想要什么：当我单击卡片视图中的删除图标时，我想同时从数据库和回收站视图中删除所需的卡片视图。

问题：假设我添加了 3 个卡片视图，当我单击其中一个的删除图标时它会消失，但最后添加的卡片视图的副本出现在底部，因此卡片视图的数量保持不变（ 3 张卡片）请检查下面的图片。

回收者视图适配器的代码：

class BillsAdapter(val bills: List<Bill>) : RecyclerView.Adapter<BillsAdapter.BillViewHolder>() {

private var mListener: OnItemClickListener? = null

interface OnItemClickListener {
    fun onDeleteClick(position: Int)
}

fun setOnClickListener(listener: OnItemClickListener) {
    mListener = listener
}

class BillViewHolder( val card: View, listener: OnItemClickListener?) : RecyclerView.ViewHolder(card) {
    var mDeleteImage: ImageView

    init {
        mDeleteImage = card.findViewById(R.id.btn_delete)

        mDeleteImage.setOnClickListener {
            if (listener != null) {
                val position = adapterPosition
                if (position != RecyclerView.NO_POSITION) {
                    listener.onDeleteClick(position)
                }
            }
        }
    }
}

override fun onBindViewHolder(holder: BillViewHolder, index: Int) {

    val bill = bills[index]

    holder.card.tv_title.text = bill.title
    holder.card.tv_description.text = bill.description


}

override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): BillViewHolder {

    val view = LayoutInflater.from(parent.context).inflate(R.layout.single_card, parent, false)

    return BillViewHolder(view, mListener)
}

override fun getItemCount(): Int = bills.size 

数据库处理程序代码：

class billDbHandler (context: Context) : SQLiteOpenHelper(context,
DATABASE_NAME, null, DATABASE_VERSION) {

private val SQL_CREATE_ENTRIES = "CREATE TABLE ${BillEntry.TABLE_NAME} (" +
        "${BillEntry._ID} INTEGER PRIMARY KEY," +
        "${BillEntry.TITLE_COL} TEXT," +
        "${BillEntry.DESCR_COL} TEXT," +
        ")"

private val SQL_DELETE_ENTRIES = "DROP TABLE IF EXISTS ${BillEntry.TABLE_NAME}"

override fun onCreate(db: SQLiteDatabase) {
    db.execSQL(SQL_CREATE_ENTRIES)
}

override fun onUpgrade(db: SQLiteDatabase, oldVersion: Int, newVersion: Int) {
    db.execSQL(SQL_DELETE_ENTRIES)
    onCreate(db)
}

}

数据库表代码：

class BillDbTable(context: Context) {

private val TAG = BillDbTable::class.java.simpleName
private val dbHelper = billDbHandler(context)

fun store(bill: Bill): Long {
    val db  = dbHelper.writableDatabase
    val values = ContentValues()

    values.put(BillEntry.TITLE_COL, bill.title)
    values.put(BillEntry.DESCR_COL, bill.description)

    val id = db.insert(BillEntry.TABLE_NAME, null,values)

    db.close()

    Log.d(TAG, "Stored new bill to DB $bill")

    return id
}

fun readAllBills(): List<Bill> {
    val columns = arrayOf(BillEntry._ID,
        BillEntry.TITLE_COL, BillEntry.DESCR_COL)

    val order = "${BillEntry._ID} ASC"

    val db= dbHelper.readableDatabase

    val cursor = db.doQuery(BillEntry.TABLE_NAME, columns, orderBy = order)

    return  parseBillsFrom(cursor)

}

fun parseBillsFrom(cursor: Cursor): MutableList<Bill> {
    val bills = mutableListOf<Bill>()
    while (cursor.moveToNext()) {
        val title = cursor.getString(BillEntry.TITLE_COL)
        val desc = cursor.getString(BillEntry.DESCR_COL)

        bills.add(Bill(title, desc))
    }
    cursor.close()

    return bills
}

fun delete() {

    val columns = arrayOf(BillEntry._ID,
        BillEntry.TITLE_COL, BillEntry.DESCR_COL)

    val order = "${BillEntry._ID} ASC"

    val db = dbHelper.writableDatabase
    val cursor = db.doQuery(BillEntry.TABLE_NAME, columns, orderBy = order)

    if (cursor.moveToNext()){
        val id = cursor.getLong(0)
        db.delete(BillEntry.TABLE_NAME, BillEntry._ID + "= ?" , arrayOf(id.toString()))
        cursor.close()
     }

    db.close()
  } }    fun SQLiteDatabase.doQuery(table: String, columns: Array<String>, selection: String? = null,
                               selectionArgs: Array<String>? = null, groupBy: String? = null,
                               having: String? = null, orderBy: String? = null): Cursor {
return query(table, columns, selection, selectionArgs, groupBy, having, orderBy)}    private fun Cursor.getString(columnName: String): String = this.getString(getColumnIndex(columnName))

主要活动代码：

class MainActivity : AppCompatActivity() {

var db = BillDbTable(this)
private var mAdapter: BillsAdapter? = null

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

    mAdapter = BillsAdapter(db.readAllBills())

    rv.setHasFixedSize(true)

    rv.layoutManager = LinearLayoutManager(this)
    rv.adapter = mAdapter

    mAdapter!!.setOnClickListener(object : BillsAdapter.OnItemClickListener {
        override fun onDeleteClick(position: Int) {
            removeCard(position)

        }
    })
}

override fun onCreateOptionsMenu(menu: Menu): Boolean {
    menuInflater.inflate(R.menu.main_menu, menu)
    return true
}

override fun onOptionsItemSelected(item: MenuItem): Boolean {
    if (item.itemId == R.id.add_bill){
        val intent = Intent(this, CreateBillActivity::class.java)
        startActivity(intent)
    }
    return true
}

fun test() {
    Toast.makeText(this, "Item Deleted", Toast.LENGTH_LONG).show()
}

fun removeCard(position: Int){

    db.delete()
    test()
    mAdapter!!.notifyItemRemoved(position)


} }

点击所有卡片的删除图标前

点击所有卡片的删除图标后