Android 扫描SDCard上的音乐文件以及监听扫描事件

时间:2022-08-05 22:41:08


广播接收机代码:

public class ScanSdReceiver extends BroadcastReceiver  
{
@Override
public void onReceive(Context context, Intent intent)
{
String action = intent.getAction();
if (Intent.ACTION_MEDIA_SCANNER_STARTED.equals(action))
{
//开始扫描,把你的代码放这里
}
else if (Intent.ACTION_MEDIA_SCANNER_FINISHED.equals(action))
{
//扫描结束,把你的代码放这里
}
}
}
注册广播接收机,监听SDcard扫描事件

IntentFilter intentfilter = new IntentFilter(Intent.ACTION_MEDIA_SCANNER_STARTED);  
intentfilter.addAction(Intent.ACTION_MEDIA_SCANNER_FINISHED);
intentfilter.addDataScheme("file");
ScanSdReceiver scanSdReceiver = new ScanSdReceiver();
registerReceiver(scanSdReceiver, intentfilter);

扫描SDCard

sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED,  
Uri.parse("file://" + Environment.getExternalStorageDirectory().getAbsolutePath())));

================================================================================

如果你做过多媒体应用,一定会苦恼过,怎样获取sd卡中的多媒体文件。android还是很强大的,如果你知道怎么调用android的api,万事就ok了。
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1  当手机或模拟器开机时,会调用android的MediaScanner,扫描sd卡和内存里的文件。以下是log信息。
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1 12-13 15:39:11.062: VERBOSE/MediaPlayerService(67): Create new media retriever from pid 349<br>
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1 12-13 15:39:11.082: DEBUG/MediaScannerService(349): getDefaultLocale =zh_CN
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1 12-13 15:39:11.122: DEBUG/SurfaceFlinger(102): Layer::requestBuffer(this=0x7c8c68), index=1, pid=12866, w=309, h=192 success
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1 12-13 15:39:11.142: INFO/MediaScanner(349): mOriginalCount = 14, prune thumb flag = false<br>
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1 12-13 15:39:11.142: DEBUG/MediaScanner(349):  prescan time: 44ms<br>
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1 12-13 15:39:11.142: DEBUG/MediaScanner(349):     scan time: 13ms<br>
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1 12-13 15:39:11.142: DEBUG/MediaScanner(349): postscan time: 2ms<br>
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1 12-13 15:39:11.142: DEBUG/MediaScanner(349):    total time: 59ms<br>
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1 12-13 15:39:11.152: DEBUG/MediaProvider(349): un-lock thumbnail worker<br>
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1 12-13 15:39:11.152: DEBUG/MediaProvider(349): un-lock thumbnail worker<br>
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1 12-13 15:39:11.182: DEBUG/MediaScannerService(349): done scanning volume external
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1 那么扫描后的记录它保存到哪里了呢。哈。你觉得在哪里呢?data/data/com.android.media/providers/databases/external
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1 它存了些什么信息呢,拉出来看看吧:
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1 <img
src=
"http://pic002.cnblogs.com/images/2010/210374/2010121315535739.gif" alt=""
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1  那么,我们直接使用ContentProvider就可以直接获取到sd卡中多媒体的信息了,你还用去listfile么?还用去自己解析媒体文件中的信息么(时长,文件名,专辑名。。应有尽有哦)?
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1 Cursor
cursor = context.getContentResolver().query(<br>    MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,<br>    
new String[] { MediaStore.Audio.Media._ID, MediaStore.Audio.Media.DISPLAY_NAME, MediaStore.Audio.Media.TITLE,<br>      MediaStore.Audio.Media.DURATION, MediaStore.Audio.Media.ARTIST, MediaStore.Audio.Media.ALBUM,<br>      MediaStore.Audio.Media.YEAR, MediaStore.Audio.Media.MIME_TYPE, MediaStore.Audio.Media.SIZE, MediaStore.Audio.Media.DATA}<br>    , "_size>?",new String[]{1024*1024+""},null);
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1  
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1 好了,最后一个问题<br> 当你往sd卡中添加一些多媒体文件的时候,android没有自动将它刷新到数据库中。那么我们怎么让它手动刷新呢,如下:
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960 IntentFilter
intentFilter =
new IntentFilter(Intent.ACTION_MEDIA_SCANNER_STARTED);
        intentFilter.addAction(Intent.ACTION_MEDIA_SCANNER_FINISHED);        intentFilter.addDataScheme("file");        scanReceiver = new ScanSdFilesReceiver();        registerReceiver(scanReceiver, intentFilter);        sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED, Uri.parse("file://" + Environment.getExternalStorageDirectory())));  private class ScanSdFilesReceiverextends BroadcastReceiver {        public void onReceive(Context context, Intent intent) {            String action = intent.getAction();            if (Intent.ACTION_MEDIA_SCANNER_STARTED.equals(action)) {                scanHandler.sendEmptyMessage(STARTED);            }            if (Intent.ACTION_MEDIA_SCANNER_FINISHED.equals(action)) {                scanHandler.sendEmptyMessage(FINISHED);            }        }    }  private Handler scanHandler = new Handler() {        public void handleMessage(Message msg) {            super.handleMessage(msg);            switch (msg.what) {            case STARTED:                MyDialog scanDialog = new MyDialog(LocalList.this);                scanAlertDialog = scanDialog.scanFile();                scanAlertDialog.show();                Log.i(TAG,"showing");                break;            case FINISHED:                ArrayList<Song> tempSongs = ReadFileList.readDataFromSD(LocalList.this, LOCAL);                if (tempSongs != null && tempSongs.size()>0) {                    if (songs != null && songs.size()>0) {                        songs.clear();                        songs.addAll(tempSongs);                        songAdapter.notifyDataSetChanged();                    }else {                        songs = new ArrayList<Song>();                        songs.addAll(tempSongs);                        initSong_lv();                    }                }else {                    Toast.makeText(LocalList.this,"SD卡中没有歌曲,请添加后再扫描", Toast.LENGTH_SHORT).show();                }                Log.i(TAG,"finish");                if (scanAlertDialog!=null && scanAlertDialog.isShowing()) {                    scanAlertDialog.dismiss();                }                unregisterReceiver(scanReceiver);                break;            case DISMISS:                Log.i(TAG,"dismiss");                if (scanAlertDialog!=null && scanAlertDialog.isShowing()) {                    scanAlertDialog.dismiss();                }            default:                break;            }