android - overridden volume button has affected back button?

Using the code below I have stopped the use of the volume buttons unless I am streaming audio (otherwise it annoyingly changes the ringer volume), but the 'Back' button isn'开发者_如何学编程t working.

Pressing 'back' should got to my phones desktop (or exit my app, like you would expect), but it isn't doing anything. If I open the menu, 'Back' will close the menu as it should, but I can't leave the app.

I have copied the code onto other activities within my app, if I open another activity within my app, because the 'Back' button isn't working, I can't go back to the main screen :)

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    //Suppress the use of the volume keys unless we are currently listening to the stream
    if(keyCode==KeyEvent.KEYCODE_VOLUME_UP) {
        if(StreamService.INT_PLAY_STATE==0){
            return true;
        }else{
            return false;
        }
    }
    if(keyCode==KeyEvent.KEYCODE_VOLUME_DOWN) {
        if(StreamService.INT_PLAY_STATE==0){
            return true;
        }else{
            return false;
        }
    }
return false;

Why is this happening?

Haven't tested, but I think you need to include an else where you call super.onKeyDown, ie:

if(keyCode == KeyEvent.KEYCODE_VOLUME_UP) {
   code
} else if (keyCode == KeyEvent.KEYCODE_VOLUME_DOWN) {
   more code
} else {
   super.onKeyDown(keyCode, event);
}

Otherwise, you're capturing all keycodes and returning false after checking the volume codes.

A simpler and more robust way to have the volume keys always control the Media volume is to insert this line into your Activity's onCreate():

setVolumeControlStream(AudioManager.STREAM_MUSIC);

Dude, just change the audio context on that activity to media volume:

http://developer.android.com/reference/android/media/AudioManager.html

EDIT:

private AudioManager audio;

Inside onCreate:

audio = (AudioManager) getSystemService(Context.AUDIO_SERVICE);

Override onKeyDown:

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    switch (keyCode) {
    case KeyEvent.KEYCODE_VOLUME_UP:
        audio.adjustStreamVolume(AudioManager.STREAM_MUSIC,
                AudioManager.ADJUST_RAISE, AudioManager.FLAG_SHOW_UI);
        return true;
    case KeyEvent.KEYCODE_VOLUME_DOWN:
        audio.adjustStreamVolume(AudioManager.STREAM_MUSIC,
                AudioManager.ADJUST_LOWER, AudioManager.FLAG_SHOW_UI);
        return true;
    default:
        return false;
    }
}

public boolean onKeyDown(int keyCode, KeyEvent event) {

    if (keyCode == KeyEvent.KEYCODE_VOLUME_UP) {
        //your code
        return true;

    } else if (keyCode == KeyEvent.KEYCODE_VOLUME_DOWN) {
        //your code
        return true;
    } else {

        super.onKeyDown(keyCode, event);
    }


    return true;

}