如何编程识别带HCE服务的NFC支付应用及设备默认支付应用？

1. 识别可用于NFC支付的应用列表及默认支付应用 #

获取支持NFC支付的应用列表 #

通过CardEmulation类可直接获取系统中注册为支付类别的HCE服务，每个服务对应一个应用：

fun getPaymentApps(context: Context): List<ApplicationInfo> {
    val cardEmulation = CardEmulation.getInstance(NfcAdapter.getDefaultAdapter(context))
    val paymentServices = cardEmulation.getServicesForCategory(CardEmulation.CATEGORY_PAYMENT)
    val packageManager = context.packageManager
    val paymentApps = mutableListOf<ApplicationInfo>()
    
    for (service in paymentServices) {
        try {
            val appInfo = packageManager.getApplicationInfo(service.packageName, 0)
            paymentApps.add(appInfo)
        } catch (e: PackageManager.NameNotFoundException) {
            e.printStackTrace()
        }
    }
    return paymentApps
}

遍历返回的ComponentName集合，通过包名即可获取对应的应用信息。

检查当前默认支付应用 #

调用getDefaultServiceForCategory方法获取默认服务，再关联到对应应用：

fun getDefaultPaymentApp(context: Context): ApplicationInfo? {
    val cardEmulation = CardEmulation.getInstance(NfcAdapter.getDefaultAdapter(context))
    val defaultService = cardEmulation.getDefaultServiceForCategory(CardEmulation.CATEGORY_PAYMENT)
    val packageManager = context.packageManager
    
    return defaultService?.let {
        try {
            packageManager.getApplicationInfo(it.packageName, 0)
        } catch (e: PackageManager.NameNotFoundException) {
            null
        }
    }
}

2. 识别具备HCE服务的可用NFC支付应用列表 #

HCE服务需在Manifest中声明android.nfc.cardemulation.action.HOST_APDU_SERVICE的Intent Filter，因此可通过PackageManager查询所有包含该过滤规则的服务，再筛选属于支付类别的：

fun getHcePaymentApps(context: Context): List<ApplicationInfo> {
    val packageManager = context.packageManager
    val intent = Intent("android.nfc.cardemulation.action.HOST_APDU_SERVICE")
    val resolveInfos = packageManager.queryIntentServices(intent, 0)
    val cardEmulation = CardEmulation.getInstance(NfcAdapter.getDefaultAdapter(context))
    val hcePaymentApps = mutableListOf<ApplicationInfo>()
    
    for (resolveInfo in resolveInfos) {
        val componentName = ComponentName(resolveInfo.serviceInfo.packageName, resolveInfo.serviceInfo.name)
        // 检查该HCE服务是否属于支付类别
        if (cardEmulation.getCategoryForService(componentName) == CardEmulation.CATEGORY_PAYMENT) {
            try {
                val appInfo = packageManager.getApplicationInfo(resolveInfo.serviceInfo.packageName, 0)
                hcePaymentApps.add(appInfo)
            } catch (e: PackageManager.NameNotFoundException) {
                e.printStackTrace()
            }
        }
    }
    return hcePaymentApps
}

补充：设置自身为默认NFC支付应用（你的实现） #

你已实现的代码可正常使用，注意需在Manifest中声明对应权限和HCE服务配置：

fun setAsDefault(context: Context) {
    try {
        val intent = Intent()
        intent.setAction(CardEmulation.ACTION_CHANGE_DEFAULT);
        intent.putExtra(
            CardEmulation.EXTRA_SERVICE_COMPONENT,
            ComponentName(
                context,
                HCEService::class.java
            )
        )
        intent.putExtra(CardEmulation.EXTRA_CATEGORY, CardEmulation.CATEGORY_PAYMENT)
        context.startActivity(intent)
    } catch (e: Exception) {
        e.printStackTrace()
    }
}

注意：使用这些API需要在Manifest中添加android.permission.NFC权限，并且确保设备支持NFC功能，调用前需检查NfcAdapter.getDefaultAdapter(context)不为null。

内容的提问来源于stack exchange，提问作者breeze