【Android】Write your own texting APP with Android

Environment: Android-studio

Android version: Android 6

1. Create a project first

2. Layout file 

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Enter the phone number of the recipient"/>

    <EditText
        android:id="@+id/phoneNo"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"/>

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Message"/>

    <EditText
        android:id="@+id/textMessage"
        android:layout_width="fill_parent"
        android:layout_height="160dp"
        android:maxLength="160"
        android:gravity="top"/>

    <TextView
        android:id="@+id/mCounter"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="160/0"/>
    <Button
        android:id="@+id/sendSMS"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Send SMS"/>

</LinearLayout>

3. Write a receiving class

package com.example.sendsms;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.telephony.SmsMessage;
import android.widget.Toast;

public class SMSReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        Bundle bundle = intent.getExtras();
        SmsMessage[] msgs = null;
        String str = "";
        if (bundle!=null){
            Object[] pdus = (Object[]) bundle.get("pdus");
            msgs = new SmsMessage[pdus.length];
            for (int i=0;i<msgs.length;i++){
                msgs[i] = SmsMessage.createFromPdu((byte[]) pdus[i]);
                str += "SMS from "+msgs[i].getOriginatingAddress();
                str += " :";
                str += msgs[i].getMessageBody().toString();
                str += "n";
            }
            Toast.makeText(context, str, Toast.LENGTH_SHORT).show();
        }
    }
}

4. The manifest file gives permissions

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.sendsms" >

    <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/Theme.Map" >
        <receiver
            android:name=".SMSReceiver"
            android:enabled="true"
            android:exported="true" >
            <intent-filter>
                <action android:name="android.provider.Telephony.SMS_RECEIVED"/>
            </intent-filter>
        </receiver>

        <activity
            android:name=".MainActivity"
            android:exported="true" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

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

</manifest>

5. Main Event

package com.example.sendsms;

import androidx.appcompat.app.AppCompatActivity;

import android.app.Activity;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.telephony.SmsManager;
import android.telephony.SmsMessage;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    Button sendSMS;
    EditText phoneNo;
    EditText textMessage;
    TextView mCounter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        sendSMS = findViewById(R.id.sendSMS);
        phoneNo = findViewById(R.id.phoneNo);
        textMessage = findViewById(R.id.textMessage);
        mCounter = findViewById(R.id.mCounter);
        textMessage.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {

            }

            @Override
            public void onTextChanged(CharSequence s, int start, int count, int after) {
                String smsLength = String.valueOf(160 - s.length());
                mCounter.setText(smsLength + "/" + s.length());

            }

            @Override
            public void afterTextChanged(Editable editable) {

            }
        });
        //发送按钮
        sendSMS.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String mobNo = phoneNo.getText().toString();
                String message = textMessage.getText().toString();
                if(mobNo.length() > 0 && message.length() > 0)
                    sendSms(mobNo, message);
                else
                    Toast.makeText(getBaseContext(), "message shouldn't null.", Toast.LENGTH_SHORT).show();
            }
        });
    }

    public void sendSms(String mobNo,String message){
        String smsSent = "SMS_SENT";
        String smsDelivered = "SMS_DELIVERED";
        PendingIntent sentPI = PendingIntent.getBroadcast(this,0,new Intent(smsSent),0);
        PendingIntent deliveredPI = PendingIntent.getBroadcast(this,0,new Intent(smsDelivered),0);

        //发送结果广播
        registerReceiver(new BroadcastReceiver() {
            @Override
            public void onReceive(Context context, Intent intent) {
                switch (getResultCode()){
                    case Activity.RESULT_OK:
                        Toast.makeText(getBaseContext(), "Result OK", 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_PDI", Toast.LENGTH_SHORT).show();
                        break;
                    case SmsManager.RESULT_ERROR_RADIO_OFF:
                        Toast.makeText(getBaseContext(), "RADIO_OFF", Toast.LENGTH_SHORT).show();
                        break;
                }
            }
        },new IntentFilter(smsSent));

        //短信接收广播
        registerReceiver(new BroadcastReceiver() {
            @Override
            public void onReceive(Context arg0, Intent arg1) {
                switch (getResultCode()){
                    case Activity.RESULT_OK:
                        Toast.makeText(getBaseContext(), "SMS delivered", Toast.LENGTH_SHORT).show();
                        break;
                    case Activity.RESULT_CANCELED:
                        Toast.makeText(getBaseContext(), "SMS not delivered", Toast.LENGTH_SHORT).show();
                        break;
                }
            }
        },new IntentFilter(smsDelivered));
        SmsManager sms = SmsManager.getDefault();
        sms.sendTextMessage(mobNo,null,message,sentPI,deliveredPI);
        Toast.makeText(getApplicationContext(), "send successful", Toast.LENGTH_SHORT).show();
    }
}

6. Run it

7. Remember to also give application permissions in the virtual machine