<?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"
  tools:context="bai.cslg.servicebestpractice.MainActivity"
  android:baselineAligned="false"
  android:orientation="vertical">


  <LinearLayout
    android:paddingTop="20dp"
    android:layout_width="match_parent"
    android:layout_height="70dp">
    <TextView
      android:layout_width="0dp"
      android:layout_height="wrap_content"
      android:layout_weight="5"
      android:padding="10dp"
      android:gravity="center_vertical"
      android:text="請設置提示時間間隔:"
      android:textSize="20sp"/>
    <EditText
      android:id="@+id/time"
      android:layout_width="0dp"
      android:layout_height="wrap_content"
      android:layout_weight="1"/>
    <TextView
      android:layout_width="0dp"
      android:layout_height="wrap_content"
      android:layout_weight="2"
      android:gravity="center_vertical"
      android:text="分"
      android:textSize="20sp"/>
  </LinearLayout>

  <LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content">
  <Button
    android:id="@+id/start_serice"
    android:layout_width="0dp"
    android:layout_height="wrap_content"
    android:layout_weight="1"
    android:text="開啟"/>
    <Button
      android:id="@+id/stop_serice"
      android:layout_width="0dp"
      android:layout_height="wrap_content"
      android:layout_weight="1"
      android:text="結束"/>
  </LinearLayout>
</LinearLayout>

/*
*因為要服務常駐后臺，就不需要BindService，直接StartService即可
*/
package bai.cslg.servicebestpractice;

import android.content.Context;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity implements View.OnClickListener{

  private Context mContext = MainActivity.this;

  private Button startService;
  private Button stopService;
  private EditText time;

  public static int TIME; //記錄時間間隔

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    startService = (Button) findViewById(R.id.start_serice);
    stopService = (Button) findViewById(R.id.stop_serice);
    time = (EditText) findViewById(R.id.time);

    startService.setOnClickListener(this);
    stopService.setOnClickListener(this);

  }

  @Override
  public void onClick(View view) {
    switch (view.getId()){
      case R.id.start_serice:
        Intent startIntent = new Intent(this,LongRunningService.class);
        TIME = Integer.parseInt(time.getText().toString().trim());
        //通過Intent將時間間隔傳遞給Service
        startIntent.putExtra("Time",TIME);
        Toast.makeText(MainActivity.this,"開始提醒",Toast.LENGTH_SHORT).show();
        startService(startIntent);
        break;
      case R.id.stop_serice:
        Intent stopIntent = new Intent(this,LongRunningService.class);
        Toast.makeText(MainActivity.this,"結束提醒",Toast.LENGTH_SHORT).show();
        stopService(stopIntent);
        break;
    }
  }
}

package bai.cslg.servicebestpractice;

import android.app.AlarmManager;
import android.app.AlertDialog;
import android.app.PendingIntent;
import android.app.Service;
import android.content.DialogInterface;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.os.SystemClock;
import android.support.annotation.Nullable;
import android.util.Log;
import android.view.WindowManager;



import java.io.File;
import java.io.IOException;
import java.util.Date;

/**
 * Created by baiqihui on 2016/9/21.
 */
public class LongRunningService extends Service {

  public int anHour; //記錄間隔時間

  public int number = 0; //記錄alertdialog出現次數

  private MediaPlayer mediaPlayer = new MediaPlayer();

  AlarmManager manager;
  PendingIntent pi;


  private Handler mHandler = new Handler(){
    @Override
    public void handleMessage(Message msg) {
      super.handleMessage(msg);
      switch (msg.what){
        case 1:
          if (!mediaPlayer.isPlaying()){
            mediaPlayer.start();
          }
          AlertDialog.Builder builder = new AlertDialog.Builder(LongRunningService.this);
          builder.setTitle("提醒");
          builder.setMessage("該補水啦" + (number-1));
          builder.setCancelable(false);
          builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialogInterface, int i) {
              mediaPlayer.reset();
              initMediaPlayer();
            }
          });
          final AlertDialog dialog = builder.create();
          dialog.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);
          dialog.show();
      }
    }
  };

  @Nullable
  @Override
  public IBinder onBind(Intent intent) {
    return null;
  }

  @Override
  public void onCreate() {
    super.onCreate();
    initMediaPlayer();

  }

  private void initMediaPlayer() {
    File file = new File("/storage/emulated/0/naoling","music.mp3");
    try {
      mediaPlayer.setDataSource(file.getPath());
      mediaPlayer.prepare();
    } catch (IOException e) {
      e.printStackTrace();
    }
  }

  @Override
  public int onStartCommand(Intent intent, int flags, int startId) {
    if (number!=0) {
      new Thread(new Runnable() {
        @Override
        public void run() {
          Log.e("bai", "executed at " + new Date().toString());
          mHandler.sendEmptyMessage(1);
        }
      }).start();
    }
    manager = (AlarmManager) getSystemService(ALARM_SERVICE);
    int time = intent.getIntExtra("Time",2);
    anHour = time*60*1000;
    Log.e("bai","Time:"+time+"anhour:"+anHour);
    long triggerAtTime = SystemClock.elapsedRealtime()+(anHour);
    Intent i = new Intent(this,AlarmReceiver.class);
    pi = PendingIntent.getBroadcast(this,0,i,0);
    manager.set(AlarmManager.ELAPSED_REALTIME_WAKEUP,triggerAtTime,pi);
    number++;
    return super.onStartCommand(intent, flags, startId);
  }

  @Override
  public void onDestroy() {
    super.onDestroy();
    mediaPlayer.release();
    manager.cancel(pi);
  }
}

package bai.cslg.servicebestpractice;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;

/**
 * Created by baiqihui on 2016/9/21.
 */
public class AlarmReceiver extends BroadcastReceiver {
  @Override
  public void onReceive(Context context, Intent intent) {
      Intent i = new Intent(context, LongRunningService.class);
      context.startService(i);
  }
}