在 Android 中按下后退时停止声音文件

Stop sound file when back pressed in Android

我在列表视图中有一些音频文件,我随机播放它们。在播放文件时我想按后退按钮返回,所以在 onBackpressed 方法中我输入以下内容

 if(mMediaPlayer.isPlaying())
    {
        mMediaPlayer.release();
        mMediaPlayer = null;
    }else
    {
        //show a message or something
    }

但它不起作用,如果音频未播放,我会收到致命异常 MAIN NullpointerException

试试这个代码,它可能对你有帮助

 if(mMediaPlayer!=null && mMediaPlayer.isPlaying())
    {
        mMediaPlayer.release();
        mMediaPlayer = null;
    }else
    {
        //show a message or something
    }
@Override
protected void onStop() {
super.onStop();  

if(mMediaPlayer!=null && mMediaPlayer.isPlaying())
{
mMediaPlayer.stop();
mMediaPlayer.release();
mMediaPlayer = null;
}

}

@Override
protected void onDestroy() {
 super.onDestroy();
if(mMediaPlayer!=null && mMediaPlayer.isPlaying())
{
 mMediaPlayer.stop();
 mMediaPlayer.release();
 mMediaPlayer = null;  
}
}