在Kotlin Android中获取SIM卡号的checkpermission运行时？

Question

如何在Kotlin android中获取SIM卡号

在此代码中，我无法获得权限框，而吐司仅显示消息，而不显示任何phome号

class MainActivity : AppCompatActivity() {
    private var wantPermission = Manifest.permission.READ_PHONE_STATE

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

        val number = getMyPhoneNO()
        Toast.makeText(applicationContext, "My Phone No is: $number", Toast.LENGTH_SHORT).show()
        Log.v("Debug", number)

    }

    private fun getMyPhoneNO(): String {
        val mTelephonyMgr: TelephonyManager = getSystemService(Context.TELEPHONY_SERVICE) as TelephonyManager
        if (checkSelfPermission(this, wantPermission) != PackageManager.PERMISSION_GRANTED) {
            return ""
        }
        return mTelephonyMgr.line1Number
    }
}