public?class?VideoMainActivity?extends?Activity?{ private?VideoView?vv;????@Override????protected?void?onCreate(Bundle?savedInstanceState)?{????????super.onCreate(savedInstanceState);????????setContentView(R.layout.activity_main4);????????vv?=?(VideoView)this.findViewById(R.id.videoView1);????????String?uri?=?"android.resource://com.example.online/"?+?R.raw.test;????????MediaController?mc=new?MediaController(VideoMainActivity.this);????????vv.setVideoURI(Uri.parse(uri));????????vv.setMediaController(mc);????????try?{ vv.start(); }?catch?(Exception?e)?{ //?TODO?Auto-generated?catch?block e.printStackTrace(); }????}運行提示不能播放這個視頻是怎么回事啊？