短信发送器

短信发送直接调用短信管理器便可以，SmsManager sm=SmsManager.getDefault();

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity"
android:orientation="vertical">

<EditText
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:hint="请输入号码"
    android:id="@+id/et_phone"
    android:inputType="phone"/>

<EditText
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:lines="5"
    android:hint="请输入内容"
    android:gravity="top"
    android:id="@+id/et_content"/>

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="发送"
    android:onClick="send"/>

</LinearLayout>

MainActivity.java

package com.jiajing.jia.b_message;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.telephony.SmsManager;
import android.view.View;
import android.widget.EditText;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

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

    public void send(View v){

        //获取号码和短信内容
EditText et_phone= (EditText) findViewById(R.id.et_phone);
 EditText et_content= (EditText) findViewById(R.id.et_content);

        String phone=et_phone.getText().toString();
        String content=et_content.getText().toString();

        //获取短信管理器
        SmsManager sm=SmsManager.getDefault();

        //分割数组
        ArrayList<String> smss = sm.divideMessage(content);

        //for循环把集合中所有的短信全部发出去
        for (String string:smss){
            sm.sendTextMessage(phone,null,string,null,null);
        }




    }
}

获取权限

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