android - recyclerview仅在第二次单击Kotlin中的另一个按钮时显示

Question

现在，这里的问题是，每当我单击btnCash时，它都应直接在recyclerview上显示一行。但是，只有在单击btnCash后单击另一个按钮时，它才会执行此操作。

可以说我要支付2.50。输入此值后，我单击btnCash，但它尚未显示任何内容。我必须单击另一个(数字按钮0-9)以进行显示。

通过使用println，我可以看到当我点击btnCash时，它将添加到ArrayList中。

有什么解决办法吗？
为什么第一次btnCash单击时不能显示它？

任何帮助都被提出。
我有payment.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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="wrap_content"
    android:layout_height="wrap_content"
    android:background="#ecf0f1"
    android:orientation="vertical">

<android.support.v7.widget.RecyclerView
        android:id="@+id/recyclerView_payment"
        android:layout_width="match_parent"
        android:layout_height="284dp"
        android:background="@color/qtr_gray6"
        android:textSize="30sp"

        />


<android.support.constraint.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="280dp"
        android:orientation="horizontal">


    <EditText
            android:id="@+id/textPayment"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:gravity="end"
            android:hint="00.0"
            android:inputType="numberDecimal"
            android:paddingRight="30dp"
            android:textAlignment="textEnd"
            app:layout_constraintEnd_toEndOf="parent" />
</android.support.constraint.ConstraintLayout>

<LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="340dp"
        android:orientation="horizontal">

    <Button
            android:id="@+id/btnFifty"
            android:layout_width="20dp"
            android:layout_height="match_parent"
            android:layout_margin="1dp"
            android:layout_weight="0.25"
            android:background="@color/qtr_primary"
            android:text="£50"
            android:textColor="#ecf0f1"
            android:textSize="20sp" />

    <Button
            android:id="@+id/btnTwenty"
            android:layout_width="20dp"
            android:layout_height="match_parent"
            android:layout_margin="1dp"
            android:layout_weight="0.25"
            android:background="@color/qtr_primary"
            android:text="£20"
            android:textColor="#ecf0f1"
            android:textSize="20sp" />

    <Button
            android:id="@+id/btnTen"
            android:layout_width="20dp"
            android:layout_height="match_parent"
            android:layout_margin="1dp"
            android:layout_weight="0.25"
            android:background="@color/qtr_primary"
            android:text="£10"
            android:textColor="#ecf0f1"
            android:textSize="20sp" />

    <Button
            android:id="@+id/btnFivePound"
            android:layout_width="20dp"
            android:layout_height="match_parent"
            android:layout_margin="1dp"
            android:layout_weight="0.25"
            android:background="@color/qtr_primary"
            android:text="£5"
            android:textColor="#ecf0f1"
            android:textSize="20sp" />

</LinearLayout>

<LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="390dp"
        android:orientation="horizontal">

    <Button
            android:id="@+id/btnOne"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_margin="1dp"
            android:layout_weight="0.25"
            android:background="@color/qtr_primary2"
            android:onClick="onDigit"
            android:text="1"
            android:textColor="#ecf0f1"
            android:textSize="20sp" />

    <Button
            android:id="@+id/btnTwo"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_margin="1dp"
            android:layout_weight="0.25"
            android:background="@color/qtr_primary2"
            android:onClick="onDigit"
            android:text="2"
            android:textColor="#ecf0f1"
            android:textSize="20sp" />

    <Button
            android:id="@+id/btnThree"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_margin="1dp"
            android:layout_weight="0.25"
            android:background="@color/qtr_primary2"
            android:onClick="onDigit"
            android:text="3"
            android:textColor="#ecf0f1"
            android:textSize="20sp" />

    <Button
            android:id="@+id/btnBack"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_margin="1dp"
            android:layout_weight="0.25"
            android:background="@color/qtr_btn8"
            android:onClick="onBack"
            android:text="Back"
            android:textColor="#ecf0f1"
            android:textSize="14sp" />

</LinearLayout>

<LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="442dp"
        android:orientation="horizontal">

    <Button
            android:id="@+id/btnFour"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_margin="1dp"
            android:layout_weight="0.25"
            android:background="@color/qtr_primary2"
            android:onClick="onDigit"
            android:text="4"
            android:textColor="#ecf0f1"
            android:textSize="20sp" />

    <Button
            android:id="@+id/btnFive"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_margin="1dp"
            android:layout_weight="0.25"
            android:background="@color/qtr_primary2"
            android:onClick="onDigit"
            android:text="5"
            android:textColor="#ecf0f1"
            android:textSize="20sp" />

    <Button
            android:id="@+id/btnSix"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_margin="1dp"
            android:layout_weight="0.25"
            android:background="@color/qtr_primary2"
            android:onClick="onDigit"
            android:text="6"
            android:textColor="#ecf0f1"
            android:textSize="20sp" />

    <Button
            android:id="@+id/btnStaff"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_margin="1dp"
            android:layout_weight="0.25"
            android:background="@color/qtr_btn9"
            android:onClick="onStaff"
            android:text="Staff"
            android:textColor="#ecf0f1"
            android:textSize="14sp" />

</LinearLayout>

<LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="495dp"
        android:orientation="horizontal">

    <Button
            android:id="@+id/btnSeven"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_margin="1dp"
            android:layout_weight="0.25"
            android:background="@color/qtr_primary2"
            android:onClick="onDigit"
            android:text="7"
            android:textColor="#ecf0f1"
            android:textSize="20sp" />

    <Button
            android:id="@+id/btnEight"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_margin="1dp"
            android:layout_weight="0.25"
            android:background="@color/qtr_primary2"
            android:onClick="onDigit"
            android:text="8"
            android:textColor="#ecf0f1"
            android:textSize="20sp" />

    <Button
            android:id="@+id/btnNine"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_margin="1dp"
            android:layout_weight="0.25"
            android:background="@color/qtr_primary2"
            android:onClick="onDigit"
            android:text="9"
            android:textColor="#ecf0f1"
            android:textSize="20sp" />

    <Button
            android:id="@+id/btnVoucher"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_margin="1dp"
            android:layout_weight="0.25"
            android:background="@color/qtr_btn10"

            android:onClick="onVoucher"
            android:text="Voucher"
            android:textColor="#ecf0f1"
            android:textSize="14sp" />

</LinearLayout>

<LinearLayout

        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="547dp"
        android:orientation="horizontal">

    <Button
            android:id="@+id/btnZero"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_margin="1dp"
            android:layout_weight="0.25"
            android:background="@color/qtr_primary2"
            android:onClick="onDigit"
            android:text="0"
            android:textColor="#ecf0f1"
            android:textSize="20sp" />

    <Button
            android:id="@+id/btnClear"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_margin="1dp"
            android:layout_weight="0.25"
            android:background="@color/qtr_primary2"
            android:onClick="onClear"
            android:text="cl"
            android:textColor="#ecf0f1"
            android:textSize="20sp" />

    <Button
            android:id="@+id/btnCard"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_margin="1dp"
            android:layout_weight="0.25"
            android:background="@color/qtr_btn6"
            android:onClick="onClick_Action_Function"
            android:text="Card"
            android:textColor="#ecf0f1"
            android:textSize="30sp" />

    <Button
            android:id="@+id/btnCash"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_margin="1dp"
            android:layout_weight="0.25"
            android:clickable="true"
            android:background="@color/qtr_btn7"
            android:text="Cash"
            android:textColor="#ecf0f1"
            android:textSize="30sp" />

</LinearLayout>

和PaymentActivity.kt

package com.soyut.su.epos01

import android.os.Bundle
import android.support.v7.app.AppCompatActivity
import android.text.Editable
import android.view.View
import android.widget.Button
import android.widget.EditText
import kotlinx.android.synthetic.main.payment.*
import android.text.TextWatcher
import android.support.v7.widget.LinearLayoutManager
import android.support.v7.widget.RecyclerView
import java.lang.ref.WeakReference
import java.math.BigDecimal
import java.util.*
class PaymentActivity : AppCompatActivity() {

    lateinit var pRecyclerView: RecyclerView
    lateinit var txtInput: EditText
    var lastNumeric: Boolean = false
    var stateError: Boolean = false
    var lastDot: Boolean = false
    var list = ArrayList<Payment>()

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.payment)
        txtInput = textPayment
        txtInput.addTextChangedListener(MoneyTextWatcher(txtInput))


        pRecyclerView = recyclerView_payment
        pRecyclerView.layoutManager = LinearLayoutManager(this)
        pRecyclerView.adapter = PaymentAdapter(this, list)

        btnCash.setOnClickListener {

            var paymAmnt: String = txtInput.text.toString()
            list.add(Payment("Cash", paymAmnt))


                for (i in list){
                    println(i.paymentDesc+ " - " +i.paymentAmnt)
                }

        }


    }

    fun onClick_Action_Function(view: View) {
        var paymAmnt: String = txtInput.text.toString()
        list.add(Payment("Card", paymAmnt))


    }

    fun onDigit(view: View) {

        // If not, already there is a valid expression so append to it
        txtInput.append((view as Button).text)

        // Set the flag
        lastNumeric = true
    }

    fun onBack(view: View) {
        var sz = txtInput.text.length
        println(sz)
        val textString = txtInput.getText().toString()
        if (textString.length > 0) {
            txtInput.setText(textString.substring(0, textString.length - 1))
        }


    }

    fun onClear(view: View) {
        var sz = txtInput.text.length
        txtInput.text = txtInput.text.dropLast(sz) as Editable
    }

    /**
     * Append . to the TextView
     */
    fun onDecimalPoint(view: View) {
        if (lastNumeric && !stateError && !lastDot) {
            txtInput.append(".")
            lastNumeric = false
            lastDot = true
        }
    }


    fun onOperator(view: View) {
        if (lastNumeric && !stateError) {
            txtInput.append((view as Button).text)
            lastNumeric = false
            lastDot = false    // Reset the DOT flag
        }
    }

    inner class MoneyTextWatcher(editText: EditText) : TextWatcher {
        private val editTextWeakReference: WeakReference<EditText>

        init {
            editTextWeakReference = WeakReference<EditText>(editText)
        }

        override fun beforeTextChanged(s: CharSequence, start: Int, count: Int, after: Int) {}

        override fun onTextChanged(s: CharSequence, start: Int, before: Int, count: Int) {}

        override fun afterTextChanged(editable: Editable) {
            val editText = editTextWeakReference.get() ?: return
            val s = editable.toString()
            if (s.isEmpty()) return
            editText.removeTextChangedListener(this)
            val cleanString = s.replace("[$,.]".toRegex(), "")
            val parsed = BigDecimal(cleanString).setScale(2, BigDecimal.ROUND_FLOOR)
                .divide(BigDecimal(100), BigDecimal.ROUND_FLOOR)
            // val formatted = NumberFormat.getCurrencyInstance(Locale.UK).format(parsed)
            editText.setText(parsed.toString())
            editText.setSelection(parsed.toString().length)
            editText.addTextChangedListener(this)
        }
    }


 }

最后是PaymentAdapter.kt

package com.soyut.su.epos01

import android.content.Context
import android.support.v7.widget.RecyclerView
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import kotlinx.android.synthetic.main.single_payment.view.*


class PaymentAdapter(val context: Context, val items: List<Payment>) : RecyclerView.Adapter<PaymentAdapter.PaymentViewHolder>() {
    override fun onBindViewHolder(p0: PaymentAdapter.PaymentViewHolder, p1: Int) {
        p0.bindItems(items[p1])
    }


    override fun getItemId(position: Int): Long {
        return super.getItemId(position)
    }


    override fun getItemCount(): Int {
        return items.size
    }


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



        val inflater = LayoutInflater.from(parent.context)

        val view = inflater.inflate(R.layout.single_payment, parent, false)
        view.requestFocus()



        return PaymentViewHolder(view)

    }


    inner class PaymentViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {

        fun bindItems(pym: Payment) {
            val textPaymentDesc = itemView.txtPaymentDescription
            val textPaymentAmnt = itemView.txtPaymentAmount

            textPaymentDesc.text = pym.paymentDesc
            textPaymentAmnt.text = pym.paymentAmnt


        }


    }
}

亲切的问候

Answer 1

在notifyDataSetChanged()中的add，update或delete数据之后使用data set。

尝试如下

var adapter: PaymentAdapter ?=null // decleare it before onCreate()

adapter = PaymentAdapter(this, list) // here you shoule initialize you adapter
pRecyclerView.adapter = adapter // assigne your adapter to recyclerview

btnCash.setOnClickListener {

        var paymAmnt: String = txtInput.text.toString()
        list.add(Payment("Cash", paymAmnt))

        adapter?.notifyDataSetChanged() // add this line to notify your adapter that data set is changed.

        //....
}