用服务打造自定义音乐播放器

自定义音乐播放器

本节通过服务与 SeekBar 的使用完成自定义音乐播放器项目
通过在 MusicService.java 文件中指定要播放音乐的路径，来选择播放网络上或者本地存储中的音乐。
注意：如果播放的是网络上的音乐，不要忘记在清单文件中添加访问网络的权限哦~

布局文件

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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:orientation="vertical">

    <Button
        android:id="@+id/play_button"
        style="@style/MyButtonStyle"
        android:text="@string/play"
        android:onClick="play"/>

    <Button
        android:id="@+id/pause_button"
        style="@style/MyButtonStyle"
        android:text="@string/pause"
        android:onClick="pause"/>

    <Button
        android:id="@+id/continue_button"
        style="@style/MyButtonStyle"
        android:text="@string/continue_button"
        android:onClick="continuePlay"/>

    <TextView
        android:id="@+id/time_textview"
        style="@style/MyButtonStyle"
        android:text="time"/>

    <SeekBar
        android:id="@+id/seekbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
</LinearLayout>

主界面

MainActivity.java

import android.content.ComponentName;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.SeekBar;
import android.widget.TextView;

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

public class MainActivity extends AppCompatActivity {
    static SeekBar seekBar;
    static TextView timeTextView;
    static Calendar calendar;
    static SimpleDateFormat simpleDateFormat = new SimpleDateFormat("mm:ss");
    MusicInterface musicInterface;
    Intent intent;
    MyServiceConnection conn;

    static Handler handler = new Handler(){
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            Bundle bundle = msg.getData();
            int max = bundle.getInt("max");
            int position = bundle.getInt("position");
            seekBar.setMax(max);
            seekBar.setProgress(position);

            //将毫秒转为相应的时间
            calendar = Calendar.getInstance();
            calendar.setTimeInMillis(max);
            Date date = calendar.getTime();
            String total = simpleDateFormat.format(date);

            calendar.setTimeInMillis(position);
            date = calendar.getTime();
            simpleDateFormat = new SimpleDateFormat("mm:ss");
            String current = simpleDateFormat.format(date);

            timeTextView.setText(current + "/" + total);
        }
    };

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

        initView();

        intent = new Intent(this, MusicService.class);
        startService(intent);
        conn = new MyServiceConnection();
        bindService(intent, conn, BIND_AUTO_CREATE);
    }

    public void initView(){
        seekBar = (SeekBar) findViewById(R.id.seekbar);
        seekBar.setOnSeekBarChangeListener(new MyOnSeekBarChangeListener());
        timeTextView= (TextView) findViewById(R.id.time_textview);
    }

    class MyOnSeekBarChangeListener implements SeekBar.OnSeekBarChangeListener{

        @Override
        public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {

        }

        @Override
        public void onStartTrackingTouch(SeekBar seekBar) {

        }

        /**
         * 当滑动seekBar松开手后触发的事件
         * @param seekBar
         */
        @Override
        public void onStopTrackingTouch(SeekBar seekBar) {
            int position = seekBar.getProgress();
            musicInterface.seekTo(position);
        }
    }

    class MyServiceConnection implements ServiceConnection{

        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            musicInterface = (MusicInterface) service;
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {

        }
    }

    /**
     * 开始播放音乐
     * @param v
     */
    public void play(View v){
        musicInterface.play();
    }

    /**
     * 暂停播放
     * @param v
     */
    public void pause(View v){
        musicInterface.pause();
    }

    /**
     * 继续播放
     * @param v
     */
    public void continuePlay(View v){
        musicInterface.continuePlay();
    }

    /**
     * 进程销毁后，解绑服务，停止服务
     */
    @Override
    protected void onDestroy() {
        super.onDestroy();
        if(conn != null) {
            unbindService(conn);
            stopService(intent);
        }
    }
}

自定义中间人接口

MusicInterface.java

public interface MusicInterface {
    void play();
    void pause();
    void continuePlay();
    void seekTo(int position);
}

自定义服务

MusicService.java

import android.app.Service;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.Binder;
import android.os.Bundle;
import android.os.IBinder;
import android.os.Message;

import java.io.IOException;
import java.util.Timer;
import java.util.TimerTask;

public class MusicService extends Service {
    MediaPlayer player;
    Timer timer;

    @Override
    public void onCreate() {
        super.onCreate();
        player = new MediaPlayer();
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        if(player != null) {
            player.stop();
            player.release();
            player = null;
        }
        if(timer != null){
            timer.cancel();
            timer = null;
        }
    }

    @Override
    public IBinder onBind(Intent intent) {
        // TODO: Return the communication channel to the service.
        return new MusicController();
    }

    class MusicController extends Binder implements MusicInterface{

        @Override
        public void play() {
            MusicService.this.play();
        }

        @Override
        public void pause() {
            MusicService.this.pause();
        }

        @Override
        public void continuePlay() {
            MusicService.this.continuePlay();
        }

        @Override
        public void seekTo(int position) {
            MusicService.this.seekTo(position);
        }
    }

    public void play(){
        if(player != null) {
            player.reset();
            try {
                //播放本地音乐
                String path = getFilesDir() + "/gaobie.mp3";
                //播放网络音乐
                //String path = "http://www.hello.com/a.mp3";
                player.setDataSource(path);
                player.prepareAsync();
                player.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
                    @Override
                    public void onPrepared(MediaPlayer mp) {
                        mp.start();
                        addTimer();
                    }
                });
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    public void pause(){
        player.pause();
    }

    public void continuePlay(){
        player.start();
    }

    /**
     * 播放指定位置的音乐
     * @param position
     */
    public void seekTo(int position){
        player.seekTo(position);
    }

    /**
     * 添加计时器，周期性的执行run方法
     */
    public void addTimer(){
        if(timer == null){
            timer = new Timer();
        }
        timer.schedule(new TimerTask() {
            @Override
            public void run() {
                Message msg = Message.obtain();
                Bundle bundle = new Bundle();
                bundle.putInt("max", player.getDuration());
                bundle.putInt("position", player.getCurrentPosition());
                msg.setData(bundle);
                MainActivity.handler.sendMessage(msg);
            }
        }, 5, 500);
    }
}

最终效果