在最近自己写的一个项目中, 遇到了这样一个问题,扫描系统SD卡中的图片文件,并按照时间进行排序,通常就是发送一个特定的广播Intent.ACTION_MEDIA_MOUNTED来通知系统执行扫描,例如
mContext.sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED, <span style="font-family: Arial, Helvetica, sans-serif;">Uri.parse("file://" + Environment.getExternalStorageDirectory())));</span>这样子,就可以满足要求了, 可是最近把手机升级到了4.4.4后发现,这个方法不好使了,一执行就报错 ,错误如下
07-08 13:34:24.211: W/System.err(23751): Caused by: java.lang.SecurityException: Permission Denial: not allowed to send broadcast android.intent.action.MEDIA_MOUNTED from pid=23751, uid=10246意思是没有权限发送这样的一条广播了,后来在stackoverflow中查找,发现在4.4[KK]后Intent.ACTION_MEDIA_MOUNTED这条Intent广播是受保护的,意思是只有系统应用才有权限使用广播通知系统扫描SD卡
<protected-broadcast android:name="android.intent.action.MEDIA_MOUNTED" />下面给出我的解决方法:
4.4 之前:
private LinkedList<PictureItem> getPictureBeforeKK() { LinkedList<PictureItem> items = null; mContext.sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED, Uri.parse("file://" + Environment.getExternalStorageDirectory()))); Uri mImageUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI; ContentResolver mContentResolver = mContext.getContentResolver(); Cursor mCursor = mContentResolver.query(mImageUri, null, null, null, MediaStore.Images.Media.DATE_ADDED); if (mCursor != null && mCursor.getCount() > 0) { items = new LinkedList<PictureItem>(); mCursor.moveToFirst(); while (mCursor.moveToNext()) { // 获取图片的路径 String path = mCursor.getString(mCursor.getColumnIndex(MediaStore.Images.Media.DATA)); // 获取图片的添加到系统的毫秒数 long time = mCursor.getLong(mCursor.getColumnIndex(MediaStore.Images.Media.DATE_ADDED)); PictureItem item = new PictureItem(path, parseTimeToYMD(time)); System.out.println("item = " + item); items.add(item); } mCursor.close(); } return items; }4.4
private LinkedList<PictureItem> getPictureInKK() { LinkedList<PictureItem> items = null; mContext.sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.parse("file://" + Environment.getExternalStorageDirectory()))); Uri mImageUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI; ContentResolver mContentResolver = mContext.getContentResolver(); Cursor mCursor = mContentResolver.query(mImageUri, null, null, null, MediaStore.Images.Media.DATE_ADDED); if (mCursor != null && mCursor.getCount() > 0) { items = new LinkedList<PictureItem>(); mCursor.moveToFirst(); while (mCursor.moveToNext()) { // 获取图片的路径 String path = mCursor.getString(mCursor.getColumnIndex(MediaStore.Images.Media.DATA)); // 获取图片的添加到系统的毫秒数 long time = mCursor.getLong(mCursor.getColumnIndex(MediaStore.Images.Media.DATE_ADDED)); PictureItem item = new PictureItem(path, parseTimeToYMD(time)); System.out.println("item = " + item); items.add(item); } mCursor.close(); } return items; }
public String parseTimeToYMD(long time) { System.setProperty("user.timezone", "Asia/Shanghai"); TimeZone tz = TimeZone.getTimeZone("Asia/Shanghai"); TimeZone.setDefault(tz); SimpleDateFormat format = new SimpleDateFormat("yyyy年MM月dd日"); return format.format(new Date(time * 1000L)); }注意加入相应的访问权限!