Android利用SeekBar实现简单音乐播放器

package my.com.mymusicp;import android.app.Service;import android.content.Intent;import android.media.MediaPlayer;import android.os.Bundle;import android.os.IBinder;import android.os.Message;import android.os.RemoteException;import android.support.annotation.Nullable;import android.util.Log;import java.io.IOException;import java.util.Timer;import java.util.TimerTask;/** * Created by c_ljf on 16-12-26. */public class MyMusicService extends Service {  private String tag="MyMusicService";  private MediaPlayer mediaPlayer;  @Override  public void onCreate() {    super.onCreate();    mediaPlayer = new MediaPlayer();  }  @Nullable  @Override  public IBinder onBind(Intent intent) {    return new MyMusicBinder();  }  class MyMusicBinder extends IMyMusicService.Stub{    @Override    public void play() throws RemoteException {      playmusic();    }    @Override    public void pause() throws RemoteException {     pausemusic();    }    @Override    public void stop() throws RemoteException {      stopmusic();    }    @Override    public void continuePlay() throws RemoteException {      rePlayMusic();    }    @Override    public void seekPlayProgress(int position) throws RemoteException {      seekPlayPositiom(position);    }  }  //播放音乐  public void playmusic(){    mediaPlayer.reset();    String url = "sdcard/Music/Fade.mp3";    Log.i(tag,url);    try {      mediaPlayer.setDataSource(url);      mediaPlayer.prepare();    } catch (IOException e) {      e.printStackTrace();    }     // might take long! (for buffering, etc)    mediaPlayer.start();    //更新播放进度条    seekPlayProgress();  }  public void pausemusic(){    mediaPlayer.pause();    Log.i(tag,"暂停播放");  }  public void stopmusic(){    mediaPlayer.reset();    Log.i(tag,"停止播放");    mediaPlayer.stop();  }  @Override  public void onDestroy() {    super.onDestroy();  }  public void seekPlayPositiom(int positon){    Log.i(tag,"设置播放位置");    mediaPlayer.seekTo(positon);  }  public void seekPlayProgress(){     /*1.获取当前歌曲的总时长*/    final int duration=mediaPlayer.getDuration();    //计时器对象    final Timer timer=new Timer();    final TimerTask task=new TimerTask() {      @Override      public void run() {        //开启线程定时获取当前播放进度        int currentposition=mediaPlayer.getCurrentPosition();        //利用message给主线程发消息更新seekbar进度        Message ms=Message.obtain();        Bundle bundle=new Bundle();        bundle.putInt("duration",duration);        Log.i(tag,"歌曲总长度"+duration);        bundle.putInt("currentposition",currentposition);        Log.i(tag,"当前长度"+currentposition);        //设置发送的消息内容        ms.setData(bundle);        //发送消息        MainActivity.handler.sendMessage(ms);      }    };     timer.schedule(task,300,500);    //当播放结束时停止播放    mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {      @Override      public void onCompletion(MediaPlayer mp) {        Log.i(tag,"取消计时任务");        timer.cancel();        task.cancel();      }    });  }  public void rePlayMusic() {    Log.i(tag, "继续播放音乐");    mediaPlayer.start();  }}

package my.com.mymusicp;import android.Manifest;import android.app.Activity;import android.content.ComponentName;import android.content.Intent;import android.content.ServiceConnection;import android.content.pm.PackageManager;import android.os.Bundle;import android.os.Handler;import android.os.IBinder;import android.os.Message;import android.os.RemoteException;import android.support.v4.app.ActivityCompat;import android.support.v7.app.AppCompatActivity;import android.view.View;import android.widget.Button;import android.widget.SeekBar;public class MainActivity extends AppCompatActivity {  private IMyMusicService iMyMusicService;  private static SeekBar seekBar;  private Button btpause_play;  private boolean b=true;//判断暂停和继续播放  public static Handler handler=new Handler(){    @Override    public void handleMessage(Message msg) {      //处理消息      Bundle bundle=msg.getData();      //获取歌曲长度和当前播放位置，并设置到进度条上      int duration=bundle.getInt("duration");      int currentposition=bundle.getInt("currentposition");      seekBar.setMax(duration);      seekBar.setProgress(currentposition);    }  };  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    verifyStoragePermissions(MainActivity.this);    //获取播放暂停按钮    btpause_play=(Button) findViewById(R.id.bt_pause);    Intent intent=new Intent(MainActivity.this,MyMusicService.class);    bindService(intent,new MyConn(),BIND_AUTO_CREATE);    seekBar=(SeekBar) findViewById(R.id.seekBar);    seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {      @Override      public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {      }      @Override      public void onStartTrackingTouch(SeekBar seekBar) {      }      @Override      public void onStopTrackingTouch(SeekBar seekBar) {        try {          iMyMusicService.seekPlayProgress(seekBar.getProgress());        } catch (RemoteException e) {          e.printStackTrace();        }      }    });  }   //定义服务连接类  class MyConn implements ServiceConnection{    @Override    public void onServiceConnected(ComponentName name, IBinder service) {      iMyMusicService=IMyMusicService.Stub.asInterface(service);    }    @Override    public void onServiceDisconnected(ComponentName name) {    }  }  public void play(View v){    try {      iMyMusicService.play();    } catch (RemoteException e) {      e.printStackTrace();    }  }  public void pause(View v){    try {      if(b)      {       iMyMusicService.pause();        b=false;        btpause_play.setText("继续播放");      }      else{         b=true;        iMyMusicService.continuePlay();        btpause_play.setText("暂停播放");      }    } catch (RemoteException e) {      e.printStackTrace();    }  }  public void stop(View v){    try {        iMyMusicService.stop();    } catch (RemoteException e) {      e.printStackTrace();    }  }  // Storage Permissions  private static final int REQUEST_EXTERNAL_STORAGE = 1;  private static String[] PERMISSIONS_STORAGE = {      Manifest.permission.READ_EXTERNAL_STORAGE,      Manifest.permission.WRITE_EXTERNAL_STORAGE,  };  /**   * Checks if the app has permission to write to device storage   *   * If the app does not has permission then the user will be prompted to grant permissions   *   * @param activity   */  public static void verifyStoragePermissions(Activity activity) {    // Check if we have write permission    int permission = ActivityCompat.checkSelfPermission(activity, Manifest.permission.WRITE_EXTERNAL_STORAGE);    if (permission != PackageManager.PERMISSION_GRANTED) {      // We don't have permission so prompt the user      ActivityCompat.requestPermissions(          activity,          PERMISSIONS_STORAGE,          REQUEST_EXTERNAL_STORAGE      );    }  }} 

<?xml version="1.0" encoding="utf-8"?><RelativeLayout  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="my.com.mymusicp.MainActivity">  <LinearLayout    android:orientation="horizontal"    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:layout_alignParentTop="true"    android:layout_alignParentLeft="true"    android:layout_alignParentStart="true"    android:id="@+id/linearLayout">    <Button      android:layout_width="wrap_content"      android:layout_height="wrap_content"      android:layout_weight="1"      android:text="开始播放"      android:onClick="play"      android:id="@+id/bt_start"/>    <Button      android:layout_width="wrap_content"      android:layout_height="wrap_content"      android:text="暂停播放"      android:layout_weight="1"      android:onClick="pause"      android:id="@+id/bt_pause"/>    <Button      android:layout_width="wrap_content"      android:layout_height="wrap_content"      android:layout_weight="1"      android:text="停止播放"      android:onClick="stop"      android:id="@+id/bt_stop"/>  </LinearLayout>  <SeekBar    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:id="@+id/seekBar"    android:layout_below="@+id/linearLayout"    android:layout_alignParentLeft="true"    android:layout_alignParentStart="true"/></RelativeLayout> 

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"     package="my.com.mymusicp"><uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>  <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>  <application    android:allowBackup="true"    android:icon="@mipmap/ic_launcher"    android:label="@string/app_name"    android:supportsRtl="true"    android:theme="@style/AppTheme">    <activity android:name=".MainActivity">      <intent-filter>        <action android:name="android.intent.action.MAIN"/>        <category android:name="android.intent.category.LAUNCHER"/>      </intent-filter>    </activity>    <service android:name=".MyMusicService"/>  </application></manifest>