android - 当我在 Android Studio 的异步线程中调用 Toast.makeText 时，会导致应用程序崩溃吗？

Question

以下代码是关于基于 Google 应用内支付的办公示例 code .
我必须在真正的手机上测试它，因为很难在 Android Studio 模拟器中测试 Google 应用内支付。
不幸的是，当我打开FragmentBuy时，应用程序在真实手机中崩溃了。 ，我几乎没有得到有关崩溃的错误信息。
我再次检查了我的代码，我发现有两个地方导致崩溃，一个是 private fun processPurchases(purchasesResult: Set<Purchase>) , 另一个是 private fun acknowledgeNonConsumablePurchasesAsync(nonConsumables: List<Purchase>) .
1:他们发射Toast.makeTex在异步线程中，是崩溃的原因吗？
2:Billing.getInstance(requireActivity(), getString(R.string.skuRegisterApp))之间哪一个是正确的和 Billing.getInstance(requireContext), getString(R.string.skuRegisterApp)) ?
3:我的代码还有其他问题吗？
FragmentBuy.kt

class FragmentBuy : Fragment() {

    private lateinit var binding: LayoutBuyBinding

    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
        binding = DataBindingUtil.inflate(
            inflater, R.layout.layout_buy, container, false
        )
   
        val mBilling=Billing.getInstance(requireActivity(), getString(R.string.skuRegisterApp)) // or Billing.getInstance(requireContext), getString(R.string.skuRegisterApp))

        mBilling.initBillingClient()

        binding.btnPurchase.setOnClickListener {
           mBilling.purchaseProduct(requireActivity())
        }

        return binding.root
    }

}

fun Context.toast(msg: String){
    Toast.makeText(this, msg, Toast.LENGTH_LONG).show()
}


fun Fragment.toast(@StringRes resId: Int) {
    toast(requireContext().getString(resId))
}

计费.kt

class Billing private constructor (private val mContext: Context, private val purchaseItem :String)
        :PurchasesUpdatedListener, BillingClientStateListener   {

     private lateinit var playStoreBillingClient: BillingClient
     private val mapSkuDetails = mutableMapOf<String,SkuDetails>()

     fun initBillingClient() {
         playStoreBillingClient = BillingClient
             .newBuilder(mContext)
             .enablePendingPurchases() // required or app will crash
             .setListener(this)
             .build()

         if (!playStoreBillingClient.isReady) {
             playStoreBillingClient.startConnection(this)
         }
     }

    override fun onBillingSetupFinished(billingResult: BillingResult) {
        when (billingResult.responseCode) {
            BillingClient.BillingResponseCode.OK -> {
                querySkuDetailsAsync(BillingClient.SkuType.INAPP, listOf(purchaseItem) )
                queryAndProcessPurchasesAsync()
                mContext.toast(R.string.msgBillINIOK)
            }
            ...
        }
    }

    private fun querySkuDetailsAsync(@BillingClient.SkuType skuType: String, skuList: List<String>) {
        val params = SkuDetailsParams.newBuilder().setSkusList(skuList).setType(skuType).build()
        playStoreBillingClient.querySkuDetailsAsync(params) { billingResult, skuDetailsList ->
            when (billingResult.responseCode) {
                BillingClient.BillingResponseCode.OK -> {
                    if (skuDetailsList.orEmpty().isNotEmpty()) {
                        skuDetailsList?.forEach {
                            mapSkuDetails.put(it.sku,it)
                        }
                    }
                }
                '''
            }
        }
    }

    private fun queryAndProcessPurchasesAsync() {
        val purchasesResult = HashSet<Purchase>()
        var result = playStoreBillingClient.queryPurchases(BillingClient.SkuType.INAPP)
        result?.purchasesList?.apply { purchasesResult.addAll(this) }

        processPurchases(purchasesResult)
    }


    private fun processPurchases(purchasesResult: Set<Purchase>): Job {
        return CoroutineScope(Job() + Dispatchers.IO).launch {
            val validPurchases = HashSet<Purchase>(purchasesResult.size)
            purchasesResult.forEach { purchase ->
                if (purchase.purchaseState == Purchase.PurchaseState.PURCHASED) {
                    if (purchase.sku.equals(purchaseItem)) {
                        if (isSignatureValid(purchase)) {
                            validPurchases.add(purchase)
                            setIsRegisteredAppAsTrue(mContext)
                            mContext.toast(R.string.msgOrderOK)  //Will it be crash?
                        }
                    }
                }
                ...

            }
            acknowledgeNonConsumablePurchasesAsync(validPurchases.toList())
        }
    }


    private fun acknowledgeNonConsumablePurchasesAsync(nonConsumables: List<Purchase>) {
        nonConsumables.forEach { purchase ->
            val params = AcknowledgePurchaseParams.newBuilder()
                           .setPurchaseToken(purchase
                           .purchaseToken).build()

            playStoreBillingClient.acknowledgePurchase(params) { billingResult ->
                when (billingResult.responseCode) {
                    BillingClient.BillingResponseCode.OK -> {
                         mContext.toast(R.string.msgOrderAcknowledgeOK)     //Will it be crash?
                    }
                    else -> mContext.toast(R.string.msgOrderAcknowledgeError, billingResult.debugMessage)
                }
            }
        }
    }



    //执行playStoreBillingClient.launchBillingFlow(...)后 launch
    override fun onPurchasesUpdated(billingResult: BillingResult, purchases: MutableList<Purchase>?) {
        when (billingResult.responseCode) {
            BillingClient.BillingResponseCode.OK -> {
                purchases?.apply { processPurchases(this.toSet()) }
            }
            ...
        }
    }


    fun purchaseProduct(activity: Activity) {
        val skuDetails = mapSkuDetails[purchaseItem]
        skuDetails?.let{
            val purchaseParams = BillingFlowParams.newBuilder().setSkuDetails(skuDetails).build()
            playStoreBillingClient.launchBillingFlow(activity, purchaseParams)
        }
    }


    companion object {
        private const val LOG_TAG = "BillingRepository"

        private var INSTANCE: Billing? = null
        fun getInstance(mContext: Context, purchaseItem: String): Billing =
                     INSTANCE ?: synchronized(this) {
                         INSTANCE ?: Billing(mContext, purchaseItem).also { INSTANCE = it }
                     }
    }


}

Answer 1

是的。您只能显示来自主 UI 线程的 toast 消息。要从任何其他线程启动 toask 消息，您可以使用 Hander，如下所示:

 new Handler(Looper.getMainLooper()).post(() -> {
        Toast.makeText(someContext, "some toast", Toast.LENGTH_SHORT).show();
 });

此外，您必须使用 Activity 上下文，而不是 fragment 上下文。
要从 fragment 中获取 Activity 上下文，您可以使用:

getActivity()

所以你可以在你的 fragment 中做这样的事情:

 new Handler(Looper.getMainLooper()).post(() -> {
            Toast.makeText(getActivity(), "some toast", Toast.LENGTH_SHORT).show();
 });

由于您使用的是扩展功能，因此您需要将其更改为使用 Activity 上下文:

fun Fragment.toast(@StringRes resId: Int) {
    getActivity().toast(requireContext().getString(resId))
}

然后你可以在你的处理程序中使用 toast() (从不同的线程显示它):

 new Handler(Looper.getMainLooper()).post(() -> {
        toast("some toast")
 });

第一个更正确，但您应该在 Activity 的上下文中使用 getString() :

Billing.getInstance(requireActivity(),getActivity().getString(R.string.skuRegisterApp))

其他一切似乎都很好