对于android版本>= LOLLIPOP_MR1:

增加权限:

叫它:

 val subscriptionManager =
        getSystemService(Context.TELEPHONY_SUBSCRIPTION_SERVICE) as SubscriptionManager
    
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.READ_PHONE_STATE) == PackageManager.PERMISSION_GRANTED) {
        
val list = subscriptionManager.activeSubscriptionInfoList
        for (info in list) {
            Log.d(TAG, "number " + info.number)
            Log.d(TAG, "network name : " + info.carrierName)
            Log.d(TAG, "country iso " + info.countryIso)
        }
    }

TelephonyManager不是正确的解决方案，因为在某些情况下，号码没有存储在SIM卡中。我建议您在应用程序第一次打开时使用共享首选项存储用户的电话号码，并且在需要时使用该号码。

private String getMyPhoneNumber(){
    TelephonyManager mTelephonyMgr;
    mTelephonyMgr = (TelephonyManager)
        getSystemService(Context.TELEPHONY_SERVICE); 
    return mTelephonyMgr.getLine1Number();
}

private String getMy10DigitPhoneNumber(){
    String s = getMyPhoneNumber();
    return s != null && s.length() > 2 ? s.substring(2) : null;
}

代码摘自http://www.androidsnippets.com/get-my-phone-number

以下是我找到的解决方案的组合(这里是示例项目，如果你也想检查自动填充):

清单

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

build.gradle

    implementation "com.google.android.gms:play-services-auth:17.0.0"

MainActivity.kt

class MainActivity : AppCompatActivity() {
    private lateinit var googleApiClient: GoogleApiClient

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        tryGetCurrentUserPhoneNumber(this)
        googleApiClient = GoogleApiClient.Builder(this).addApi(Auth.CREDENTIALS_API).build()
        if (phoneNumber.isEmpty()) {
            val hintRequest = HintRequest.Builder().setPhoneNumberIdentifierSupported(true).build()
            val intent = Auth.CredentialsApi.getHintPickerIntent(googleApiClient, hintRequest)
            try {
                startIntentSenderForResult(intent.intentSender, REQUEST_PHONE_NUMBER, null, 0, 0, 0);
            } catch (e: IntentSender.SendIntentException) {
                Toast.makeText(this, "failed to show phone picker", Toast.LENGTH_SHORT).show()
            }
        } else
            onGotPhoneNumberToSendTo()

    }

    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
        super.onActivityResult(requestCode, resultCode, data)
        if (requestCode == REQUEST_PHONE_NUMBER) {
            if (resultCode == Activity.RESULT_OK) {
                val cred: Credential? = data?.getParcelableExtra(Credential.EXTRA_KEY)
                phoneNumber = cred?.id ?: ""
                if (phoneNumber.isEmpty())
                    Toast.makeText(this, "failed to get phone number", Toast.LENGTH_SHORT).show()
                else
                    onGotPhoneNumberToSendTo()
            }
        }
    }

    private fun onGotPhoneNumberToSendTo() {
        Toast.makeText(this, "got number:$phoneNumber", Toast.LENGTH_SHORT).show()
    }


    companion object {
        private const val REQUEST_PHONE_NUMBER = 1
        private var phoneNumber = ""

        @SuppressLint("MissingPermission", "HardwareIds")
        private fun tryGetCurrentUserPhoneNumber(context: Context): String {
            if (phoneNumber.isNotEmpty())
                return phoneNumber
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                val subscriptionManager = context.getSystemService(Context.TELEPHONY_SUBSCRIPTION_SERVICE) as SubscriptionManager
                try {
                    subscriptionManager.activeSubscriptionInfoList?.forEach {
                        val number: String? = it.number
                        if (!number.isNullOrBlank()) {
                            phoneNumber = number
                            return number
                        }
                    }
                } catch (ignored: Exception) {
                }
            }
            try {
                val telephonyManager = context.getSystemService(Context.TELEPHONY_SERVICE) as TelephonyManager
                val number = telephonyManager.line1Number ?: ""
                if (!number.isBlank()) {
                    phoneNumber = number
                    return number
                }
            } catch (e: Exception) {
            }
            return ""
        }
    }
}

有一个新的Android api，允许用户选择他们的电话号码，而不需要权限。来看看: https://android-developers.googleblog.com/2017/10/effective-phone-number-verification.html

// Construct a request for phone numbers and show the picker
private void requestHint() {
    HintRequest hintRequest = new HintRequest.Builder()
       .setPhoneNumberIdentifierSupported(true)
       .build();

    PendingIntent intent = Auth.CredentialsApi.getHintPickerIntent(
        apiClient, hintRequest);
    startIntentSenderForResult(intent.getIntentSender(),
        RESOLVE_HINT, null, 0, 0, 0);
} 

while working on a security app which needed to get the phone number of who so ever my phone might get into their hands, I had to do this; 1. receive Boot completed and then try getting Line1_Number from telephonyManager which returns a string result. 2. compare the String result with my own phone number and if they don't match or string returns null then, 3. secretly send an SMS containing the string result plus a special sign to my office number. 4. if message sending fails, start a service and keep trying after each hour until sent SMS pending intent returns successful. With this steps I could get the number of the person using my lost phone. it doesn't matter if the person is charged.