Ошибка "общего сбоя" при отправке SMS

Question

Я пытаюсь отправить сообщение с одного устройства на другое с помощью диспетчера SMS.

Код успешно компилируется, но приложение может отправлять сообщения на номер 121 только при попытке ввода с другим номером, я получаю общую ошибку сбоя.

Что я делаю неправильно в следующем коде.

Android Manifest.xml

< ? xml version = "1.0"
encoding = "utf-8" ? >
 < manifest xmlns : android = "http://schemas.android.com/apk/res/android"
package = "com.example.admin.sms" >
 < uses - permission android: name = "android.permission.SEND_SMS" / >
 < uses - permission android: name = "android.permission.RECEIVE_SMS" / >
 < application
android: allowBackup = "true"
android: icon = "@mipmap/ic_launcher"
android: label = "@string/app_name"
android: roundIcon = "@mipmap/ic_launcher_round"
android: supportsRtl = "true"
android: theme = "@style/AppTheme" >
 < activity android: name = ".MainActivity" >
 < intent - filter >
 < action android: name = "android.intent.action.MAIN" / >

 < category android: name = "android.intent.category.LAUNCHER" / >
 < /intent-filter> < /activity> < /application>

< /manifest>

Файл main.java выглядит следующим образом.

package com.example.admin.sms;


import android.os.Bundle;
import android.app.Activity;
import android.app.PendingIntent;
import android.view.Menu;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import android.content.*;
import android.telephony.SmsManager;
import android.view.View;
import android.content.BroadcastReceiver;
import android.content.Intent;
import android.content.Context;
import android.content.IntentFilter;

public class MainActivity extends Activity {
    EditText phoneNumber,message;
    BroadcastReceiver sentReceiver,deliveredReceiver;
    String SENT="SMS_SENT";
    String DELIVERED = "SMS_DELIVERED";


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        final PendingIntent sentPendIntent = PendingIntent.getBroadcast(this, 0, new Intent(SENT), 0);
        final PendingIntent delivered_pendintent = PendingIntent.getBroadcast(this, 0, new Intent(DELIVERED), 0);
        sentReceiver = new BroadcastReceiver() {
            public void onReceive(Context arg0, Intent arg1) {
                switch (getResultCode()) {
                    case Activity.RESULT_OK:
                        Toast.makeText(getBaseContext(), "SMS sent", Toast.LENGTH_SHORT).show();
                        break;
                    case SmsManager.RESULT_ERROR_GENERIC_FAILURE:
                        Toast.makeText(getBaseContext(), "Generic failure", Toast.LENGTH_SHORT).show();
                        break;
                    case SmsManager.RESULT_ERROR_NO_SERVICE:
                        Toast.makeText(getBaseContext(), "No Service", Toast.LENGTH_SHORT).show();
                        break;
                    case SmsManager.RESULT_ERROR_NULL_PDU:
                        Toast.makeText(getBaseContext(), "Null PDU", Toast.LENGTH_SHORT).show();
                        break;
                    case SmsManager.RESULT_ERROR_RADIO_OFF:
                        Toast.makeText(getBaseContext(), "Radio OFF", Toast.LENGTH_SHORT).show();
                        break;
                }
            }



        };
        deliveredReceiver = new BroadcastReceiver() {
            public void onReceive(Context arg0, Intent arg1) {
                switch (getResultCode()) {
                    case Activity.RESULT_OK:
                        Toast.makeText(getBaseContext(), "SMS successfully delivered", Toast.LENGTH_SHORT).show();
                        break;
                    case Activity.RESULT_CANCELED:
                        Toast.makeText(getBaseContext(), "Failure-SMS not delivered", Toast.LENGTH_SHORT).show();
                        break;

                }
            }

        };
        registerReceiver(sentReceiver, new IntentFilter(SENT));
        registerReceiver(deliveredReceiver, new IntentFilter(DELIVERED));
        Button sendBtn = (Button) this.findViewById(R.id.send_button);
        sendBtn.setOnClickListener(new Button.OnClickListener() {
            public void onClick(View v) {
                phoneNumber = (EditText) findViewById(R.id.recvr_no);
                message = (EditText) findViewById(R.id.txt_msg);
                if (phoneNumber.getText().toString().trim().length() > 0 && message.getText().toString().trim().length() > 0) {
                    SmsManager sms = SmsManager.getDefault();
                    sms.sendTextMessage(phoneNumber.getText().toString(), null, message.getText().toString(), sentPendIntent, delivered_pendintent);
                } else {
                    Toast.makeText(MainActivity.this, "Either phone nmber or text is missing", Toast.LENGTH_SHORT).show();

                }
            }
        });
        Button cancelBtn = (Button) this.findViewById(R.id.cancel_button);
        cancelBtn.setOnClickListener(new Button.OnClickListener() {
            public void onClick(View v) {
                phoneNumber.setText("");
                message.setText("");
            }

        });

    }

}

activity_main

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Message sending form"
        android:textSize="18sp"
        android:textStyle="bold" />
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="To"/>
    <EditText
        android:layout_height="wrap_content"
        android:layout_width="match_parent"
        android:id="@+id/recvr_no"/>
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Message:"/>
    <EditText
        android:layout_width="match_parent"
        android:layout_height="150dp"
        android:id="@+id/txt_msg"/>
    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="horizontal">

        <Button
            android:id="@+id/send_button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="40dip"
            android:onClick="onClick"
            android:paddingLeft="20dip"
            android:paddingRight="20dip"
            android:text="Send SMS" />

        <Button
            android:id="@+id/cancel_button"
            android:text="Cancel"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_toRightOf="@id/send_button"
            android:layout_marginLeft="15dip"
            android:paddingLeft="20dip"
            android:paddingRight="20dip"/>
    </RelativeLayout>
</LinearLayout>