小编Meh*_*ida的帖子

正如标题所说,我想知道的区别addValueEventListener()和addListenerForSingleValueEvent()火力地堡的.

我想通过视频来播放Firebase存储中的视频我正在尝试这样:

storageReference.getDownloadUrl().addOnSuccessListener(new OnSuccessListener<Uri>() {
                    @Override
                    public void onSuccess(Uri uri) {
                        //Toast.makeText(Chat.this, uri.toString(), Toast.LENGTH_SHORT).show();
                        MediaController mc = new MediaController(Chat.this);
                        videoView.setMediaController(mc);
                        videoView.setVideoURI(uri);
                        videoView.requestFocus();
                        //videoView.start();
                    }
                });

但它不会玩.视频是空的.