Android Kotlin -如何检测和读取收到的短信

在Android Kotlin中，可以使用Telephony库来检测和读取收到的短信。下面是一个完整的示例代码：

首先，在AndroidManifest.xml文件中添加以下权限：

<uses-permission android:name="android.permission.READ_SMS" />
<uses-permission android:name="android.permission.RECEIVE_SMS" />

然后，在你的Activity中，可以创建一个BroadcastReceiver来接收短信：

import android.content.BroadcastReceiver
import android.content.Context
import android.content.Intent
import android.provider.Telephony
import android.telephony.SmsMessage
import android.widget.Toast

class SmsReceiver : BroadcastReceiver() {

    override fun onReceive(context: Context, intent: Intent) {
        if (Telephony.Sms.Intents.SMS_RECEIVED_ACTION == intent.action) {
            val messages = Telephony.Sms.Intents.getMessagesFromIntent(intent)
            for (message in messages) {
                val smsBody = message.messageBody
                val smsSender = message.originatingAddress
                Toast.makeText(context, "收到来自 $smsSender 的短信：$smsBody", Toast.LENGTH_SHORT).show()
            }
        }
    }
}

接下来，在你的Activity中注册这个BroadcastReceiver：

import android.Manifest
import android.content.IntentFilter
import android.content.pm.PackageManager
import android.os.Bundle
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import androidx.core.app.ActivityCompat
import androidx.core.content.ContextCompat

class MainActivity : AppCompatActivity() {

    private val SMS_PERMISSION_REQUEST_CODE = 0
    private val smsReceiver = SmsReceiver()

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

        if (checkPermission()) {
            registerReceiver()
        } else {
            requestPermission()
        }
    }

    private fun checkPermission(): Boolean {
        val smsPermission = Manifest.permission.READ_SMS
        val receiveSmsPermission = Manifest.permission.RECEIVE_SMS
        val granted = PackageManager.PERMISSION_GRANTED
        return ContextCompat.checkSelfPermission(this, smsPermission) == granted &&
                ContextCompat.checkSelfPermission(this, receiveSmsPermission) == granted
    }

    private fun requestPermission() {
        ActivityCompat.requestPermissions(
            this,
            arrayOf(Manifest.permission.READ_SMS, Manifest.permission.RECEIVE_SMS),
            SMS_PERMISSION_REQUEST_CODE
        )
    }

    override fun onRequestPermissionsResult(
        requestCode: Int,
        permissions: Array<String>,
        grantResults: IntArray
    ) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults)
        if (requestCode == SMS_PERMISSION_REQUEST_CODE) {
            if (grantResults.isNotEmpty() && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                registerReceiver()
            } else {
                Toast.makeText(this, "权限被拒绝，无法接收短信", Toast.LENGTH_SHORT).show()
            }
        }
    }

    private fun registerReceiver() {
        val intentFilter = IntentFilter(Telephony.Sms.Intents.SMS_RECEIVED_ACTION)
        registerReceiver(smsReceiver, intentFilter)
    }

    override fun onDestroy() {
        super.onDestroy()
        unregisterReceiver(smsReceiver)
    }
}

上述代码中，我们在Activity的onCreate方法中首先检查是否有读取短信的权限，如果有权限则注册BroadcastReceiver，如果没有则申请权限。然后，在onRequestPermissionsResult方法中处理权限申请结果。最后，我们在onDestroy方法中取消注册BroadcastReceiver，以免内存泄漏。

请注意，由于涉及到敏感信息的读取，需要在运行时动态申请权限，并且在用户拒绝权限时给予相应的提示。