Android 扫描SDCard上的音乐文件以及监听扫描事件

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())));