package com.example.testservice;
import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.widget.Toast;
public class MyService extends Service {
  @Override
  public IBinder onBind(Intent arg0) {
    return null;
  }
  /**
   * 服务第一次创建的时候调用
   */
  @Override
  public void onCreate() {
    super.onCreate();
    Toast.makeText(this, "服务的onCreate方法被调用", Toast.LENGTH_SHORT).show();
  }
  /**
   * 服务每一次启动的时候调用
   */
  @Override
  public int onStartCommand(Intent intent, int flags, int startId) {
    Toast.makeText(this, "服务的onStartCommand方法被调用", Toast.LENGTH_SHORT).show();
    return super.onStartCommand(intent, flags, startId);
  }
  @Override
  public void onDestroy() {
    Toast.makeText(this, "服务的onDestroy方法被调用", Toast.LENGTH_SHORT).show();
    super.onDestroy();
  }
}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
  package="com.example.testservice"
  android:versionCode="1"
  android:versionName="1.0" >
  <uses-sdk
    android:minSdkVersion="8"
    android:targetSdkVersion="17" />
  <application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
      android:name="com.example.testservice.MainActivity"
      android:label="@string/app_name" >
      <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
      </intent-filter>
    </activity>
    <!-- 注册服务 -->
    <service android:name=".MyService"></service>
  </application>
</manifest>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"
  android:orientation="vertical" >
  <Button
    android:id="@+id/button1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="启动服务" />
  <Button
    android:id="@+id/button2"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="停止服务" />
</LinearLayout>

package com.example.testservice;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class MainActivity extends Activity implements OnClickListener{
  private Button startService_Button;
  private Button stopService_Button;
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    //获取开启服务按钮
    startService_Button = (Button) findViewById(R.id.button1);
    //获取停止服务按钮
    stopService_Button = (Button) findViewById(R.id.button2);
    //调用点击事件
    startService_Button.setOnClickListener(this);
    stopService_Button.setOnClickListener(this);
  }
  /**
   * 点击事件
   */
  @Override
  public void onClick(View view) {
    switch(view.getId()){
    case R.id.button1:
      //"开启服务"按钮
      Intent startIntent = new Intent(this,MyService.class);
      //开启服务
      startService(startIntent);
      break;
    case R.id.button2:
      //"停止服务"按钮
      Intent stopIntent = new Intent(this,MyService.class);
      //停止服务
      stopService(stopIntent);
      break;
    default:
      break;
    }
  }
  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
  }
}