Android MediaPlayer OnPreparedListener

问题

I am working on a simple app and using a MediaPlayer to play some background noise in 1 activity. I am reading up on MediaPlayer and am not sure whether or not to implement an OnPreparedListener to trigger the start() method. What are the pros / cons to each approach?

Approach 1:

    mediaPlayer = MediaPlayer.create(context, R.raw.sound);
    mediaPlayer.setLooping(true);
    mediaPlayer.start();

Approach 2:

    mediaPlayer = MediaPlayer.create(context, R.raw.sound);
    mediaPlayer.setLooping(true);
    mediaPlayer.setOnPreparedListener(new OnPreparedListener() {

        @Override
        public void onPrepared(MediaPlayer mp) {
            mp.start();

        }
    });

回答1:

As per the docs, calling start() is effective when you are playing locally available resources for which the MediaPlayer does not require to fetch the data and process it for playing. For example playing audio resources from raw folder.

If you are trying to play a resource from remote source, its a better practice to go for OnPreparedListener() because it might involve fetching and decoding media data.

So, if you know for sure, that your resource is locally available and is of short length, go for Approach 1. Otherwise Approach 2 would be suitable.

Ideally, I prefer this.

MediaPlayer mediaPlayer = new MediaPlayer();
mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
mediaPlayer.setDataSource(getApplicationContext(), myUri);
mediaPlayer.setOnPreparedListener(new OnPreparedListener(){

@Override
    public void onPrepared(MediaPlayer mp) {
        mp.start();
    }
});
mediaPlayer.prepareAsync();

The MediaPlayer has always been tricky for me to work with. So, I would recommend you to start with the developer docs. Go through it, understand the state diagram. I am sure it will help you in solving lot of questions which you are yet to come across.

回答2:

let say you are playing video from internet and if you direct start the player it would crash because it may be not ready to play because of some internet problem or something else. and if you use preparedlistener then it will not start the player until it is ready to play. therefore it is good to have onpreparedlistener so your activity does not crash or misbehaves.

来源：https://stackoverflow.com/questions/22827190/android-mediaplayer-onpreparedlistener

标签

android

media