Android 2.2.1在音乐开始时崩溃（）

Question

in my app I have this code:

@Override
public void onBackPressed() {
    MediaPlayer buttonBack = MediaPlayer.create(this, R.raw.button_back);   
    buttonBack.start();
    super.onBackPressed();
}

which basically play sound when you hit back button. I've tried it on my emulator (Android 4.1.2) and on my Samsung Galaxy SIII Mini (Android 4.1.2). Everything works fine, so I've sent app to my friend, who has Samsung Galaxy Mini (Android 2.2.1). He told me that he gets crash sometimes when he hit back button, so he sent me LogCat, which tell me that it throws NullPointerException on line buttonBack.start(); .

image of LogCat: http://i.stack.imgur.com/Jgz5t.jpg

I've tried to change *MediaPlayer buttonBack = MediaPlayer.create(this, R.raw.button_back);* to *MediaPlayer buttonBack = MediaPlayer.create(getApplicationContext(), R.raw.button_back);* , but it did not have any effect.

Any solution on this issue?

Answer 1

You could workaround this problem:

@Override
public void onBackPressed() {
    MediaPlayer buttonBack = MediaPlayer.create(this, R.raw.button_back);   
    if (buttonBack != null) {
        buttonBack.start();
    }
    super.onBackPressed();
}

The thing is sometimes MediaPlayer.create returns null. But I guess you can live with just not playing the sound for this case that MediaPlayer.create returns null. Alternatively you could try using a SoundPool or try playing a different sound file.