判断是否正在扫描Media文件（从系统图库源码获得）

  public static final boolean isMediaScannerScanning(final ContentResolver cr) {        boolean result = false;        final Cursor cursor = query(cr, MediaStore.getMediaScannerUri(), new String[] { MediaStore.MEDIA_SCANNER_VOLUME }, null,                null, null);        if (cursor != null) {            if (cursor.getCount() == 1) {                cursor.moveToFirst();                result = "external".equals(cursor.getString(0));            }            cursor.close();        }        Log.i("====isMediaScannerScanning======", "===result===="+result);        return result;    }

return false 没有正在扫描

return true 正在扫描