Android初学------“prepareAsync called in state 8 ”解决办法

if(mediaPlayer!=null){
			System.out.println("开始播放声音............");
			try {
//				mediaPlayer=MediaPlayer.create(MainActivity.this, R.raw.a);
//				mediaPlayer.prepare();  播放本地音乐不需要这句
				mediaPlayer.start();
			} catch (IllegalStateException e) {
				e.printStackTrace();
			} 
		}else{
			System.out.println("mediaPlayer is null ");
		}if(mediaPlayer!=null){
			System.out.println("开