music

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <Button
        android:id="@+id/start_service"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:onClick="onClick"
        android:text="播放音乐"/>

    <Button
        android:id="@+id/stop_service"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:onClick="onClick"
        android:text="Stop"/>

</LinearLayout>

package com.example.music;

import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;

public class MainActivity extends AppCompatActivity {
    private Intent mIntent;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mIntent = new Intent(this,MyService.class);
    }

    public void onClick(View view) {
        switch (view.getId()){
            case R.id.start_service:
                mIntent.putExtra("int",1);
                startService(mIntent);
                break;
            case R.id.stop_service:
                mIntent.putExtra("int",2);
                startService(mIntent);

                break;
        }
    }
}

package com.example.music;

import android.content.ComponentName;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.IBinder;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

/**
 * Created by 帅比浩宇 on 2017/12/13.
 * Service启动方式有两种
 * startService（）和bindService（）
 * startService的生命周期  onCreate（） onStartCommnud（） onDestry（）
 * binService生命周期    onBind（）  unonBind（）
 */
public class Main2Activity extends AppCompatActivity {
    private ServiceConnection sc ;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        Intent intent = new Intent(this,MyBindService.class);
        sc = new ServiceConnection() {
            @Override
            public void onServiceConnected(ComponentName componentName, IBinder iBinder) {

            }

            @Override
            public void onServiceDisconnected(ComponentName componentName) {

            }
        };
        bindService(intent,sc,BIND_AUTO_CREATE);//Activity 绑定一个服务
    }


    @Override
    protected void onDestroy() {
        super.onDestroy();
        unbindService(sc);
    }
}

package com.example.music;
import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.support.annotation.Nullable;

/**
 * Created by 帅比浩宇 on 2017/12/13.
 */

public class MyBindService extends Service {
    //绑定服务
    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }
    //解除绑定
    @Override
    public boolean onUnbind(Intent intent) {
        return super.onUnbind(intent);
    }
}

package com.example.music;

import android.app.Service;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.IBinder;
import android.support.annotation.Nullable;
import android.util.Log;
/**
 * Created by 帅比浩宇 on 2017/12/13.
 */

public class MyService extends Service {
    private MediaPlayer mplayer;
    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public void onCreate() {
        super.onCreate();
        Log.d("sxl", "onCreate: ");
        mplayer = MediaPlayer.create(this,R.raw.a);
    }

    @Override
    public void onStart(Intent intent, int startId) {
        super.onStart(intent, startId);
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.d("sxl", "onStartCommand: ");
        int i = intent.getIntExtra("int",-1);
        switch (i){
            case 1:
                musicStart();
                break;
            case 2:
                stopMusic();
                break;
//            case 3:
//                stopMusic();
//                break;
        }
        return super.onStartCommand(intent, flags, startId);
    }
    //暂停播放
    private void pauseMusic() {
        if(mplayer!=null && mplayer.isPlaying()){
            mplayer.pause();//暂停播放
        }
    }
    //停止播放
    private void stopMusic(){
        if(mplayer!=null && mplayer.isPlaying()){
            mplayer.stop();
        }
    }

    //开始播放
    private void musicStart() {

        if(!mplayer.isPlaying() && mplayer!=null){
            mplayer.start();//开始播放
        }

    }

}