android sdcard 内容侦听

public class ScreenTest extends Activity {

    class SmsContent extends ContentObserver{
        private Cursor cursor = null;
        public SmsContent(Handler handler) {
            super(handler);
        }

        /**
         * @Description 当短信表发送改变时，调用该方法
         *              需要两种权限
         *              android.permission.READ_SMS读取短信
         *              android.permission.WRITE_SMS写短信
         * @Author Snake
         * @Date 2010-1-12
         */
        @Override
        public void onChange(boolean selfChange) {
            // TODO Auto-generated method stub
            super.onChange(selfChange);
            //读取收件箱中指定号码的短信
            cursor = managedQuery(Uri.parse("content://sms/inbox"), new String[]{"_id", "address", "read"}, " address=? and read=?", new String[]{"12345678901", "0"}, "date desc");

            if (cursor != null){
                ContentValues values = new ContentValues();
                values.put("read", "1");        //修改短信为已读模式
                cursor.moveToFirst();
                while (cursor.isLast()){
                    //更新当前未读短信状态为已读
                    getContentResolver().update(Uri.parse("content://sms/inbox"), values, " _id=?", new String[]{""+cursor.getInt(0)});
                    cursor.moveToNext();
                }
            }
        }
    }

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        SmsContent content = new SmsContent(new Handler());
        //注册短信变化监听
        this.getContentResolver().registerContentObserver(Uri.parse("content://sms/"), true, content);
    }
}