Android第三次作业

播放器页面：

部分代码：

　　获取权限：

 

if(ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED){
    ActivityCompat.requestPermissions(MainActivity.this,new String[]{
            Manifest.permission.WRITE_EXTERNAL_STORAGE},1);
}else{
    init();//初始化MediaPlayer
}

　　切换歌曲：

 

public void previousMusic()throws IOException {
    try {
        currentListItme--;
        if(currentListItme<0)
        {
            currentListItme=arrayList.size()-1;
        }
        playMusic(currentListItme);
    }catch(IOException e){}

}
public void nextMusic()throws IOException {
    try {
        currentListItme++;
        if(currentListItme>=arrayList.size())
        {
            currentListItme=0;
        }
        playMusic(currentListItme);
    }catch(IOException e){}

}

　　主要代码：

 

public void init()
{


    File file = new File(Environment.getExternalStorageDirectory(),"music.mp3");
    try {
        mediaPlayer.setDataSource(file.getPath());//指定音频文件路径
        mediaPlayer.prepare();//让mediaPlayer进入准备状态
    } catch (IOException e) {
        e.printStackTrace();
    }


    mListView = (ListView) findViewById(R.id.list_view);
    adapter = new BaseAdapter() {
        @Override
        public int getCount() {
            return arrayList.size();
        }

        @Override
        public Object getItem(int position) {
            return null;
        }

        @Override
        public long getItemId(int position) {
            return 0;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            TextView MusicItem = new TextView(MainActivity.this);

            MusicItem.setText(arrayList.get(position).Name);
            MusicItem.setTextSize(30);
            return MusicItem;
        }
    };
    mListView.setAdapter(adapter);
    mListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            Toast.makeText(MainActivity.this, "开始播放:"+arrayList.get(position).Name, Toast.LENGTH_LONG).show();
            try {
                playMusic(position);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    });
}
public void playMusic(int position)throws IOException
{
    try {
        this.init();
        mediaPlayer.reset();
        mediaPlayer.setDataSource(arrayList.get(position).Url);
        mediaPlayer.prepare();
        mediaPlayer.start();
    }catch (IOException e){}
}
MediaPlayer mediaPlayer = new MediaPlayer();
public void onClick(View v) {

    switch (v.getId()) {
        case R.id.id_previous: {
            try {
                previousMusic();
            } catch (IOException e) {
                e.printStackTrace();
            }

        }
        break;
        case R.id.id_stop_play: {

            if (mediaPlayer == null ||mediaPlayer.isPlaying()) {
                mediaPlayer.pause();
            } else {
                mediaPlayer.start();
            }
        }
        break;
        case R.id.next: {

            try {
                nextMusic();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        break;
        case R.id.seekbar:
        {
            this.onStopTrackingTouch(seekBar);
        }
        default:
            break;


    }


}
public void previousMusic()throws IOException {
    try {
        currentListItme--;
        if(currentListItme<0)
        {
            currentListItme=arrayList.size()-1;
        }
        playMusic(currentListItme);
    }catch(IOException e){}

}
public void nextMusic()throws IOException {
    try {
        currentListItme++;
        if(currentListItme>=arrayList.size())
        {
            currentListItme=0;
        }
        playMusic(currentListItme);
    }catch(IOException e){}

}
public boolean onKeyDown(int keyCode,KeyEvent event)
{
    if(keyCode==KeyEvent.KEYCODE_BACK)
    {
        mediaPlayer.stop();
        mediaPlayer.release();
        this.finish();
        return true;
    }
    return super.onKeyDown(keyCode,event);


}

代码地址：https://coding.net/u/lwb1234/p/Music/git/tree/master/MyApplication3

apk下载地址：https://coding.net/u/lwb1234/p/Music/git/raw/master/1600802116.apk