OnCodeSent Firebase返回空字符串

Question

我正在使用使用Firebase的电话身份验证将SMS发送到电话号码。它正在发送带有生成数字的短信，但是当执行OnCodeSent时，返回的字符串为null，因为onVerificationCompleted也未执行，所以它也不会自动验证。

 public static void sendVerificationCode(final Activity activity, final String mobileNumber)
{


    PhoneAuthProvider.OnVerificationStateChangedCallbacks mCallbacks = new PhoneAuthProvider.OnVerificationStateChangedCallbacks() {
        @Override
        public void onVerificationCompleted(@NonNull PhoneAuthCredential phoneAuthCredential) {

            CommonMethods.createToast(activity.getApplicationContext(), "Verified");
        }

        @Override
        public void onVerificationFailed(@NonNull FirebaseException e) {

            CommonMethods.createToast(activity.getApplicationContext(), "Something went wrong, please make sure" +
                    " that you enter '+' before your country code");
        }

        @Override
        public void onCodeSent(@NonNull String s, @NonNull PhoneAuthProvider.ForceResendingToken forceResendingToken) {

            super.onCodeSent(s, forceResendingToken);
            Log.i("verificationcode", s);
            Intent goToVerificationIntent = new Intent(activity, VerificationActivity.class);
            goToVerificationIntent.putExtra("codeSent", s);
            goToVerificationIntent.putExtra("mobileNumber", mobileNumber);
            activity.startActivity(goToVerificationIntent);
            activity.finish();
        }


    };


    PhoneAuthProvider.getInstance().verifyPhoneNumber(
            mobileNumber,
            60,
            TimeUnit.SECONDS,
            activity,
            mCallbacks);

}