CODEWITHSUNDEEP
javaandroideclipsekeyevent
PeakGen
PeakGen

Reputation: 23025

Handling the Back Button

I am working on the following code:

private class HandleBackButton implements OnKeyListener
    {

        @Override
        public boolean onKey(View arg0, int arg1, KeyEvent arg2) {
            // TODO Auto-generated method stub

            if(arg1==KeyEvent.KEYCODE_BACK)
            {
                showResults(0);
            }
            return true;
        }

    }

I am somewhat new to android and my purpose is to operate the above code when the back button is clicked. User can click the back button any time. But, how can I set this listener to the Activity? I can't find something like this.setOnKeyListener().

I am using Android 2.3.3.

Upvotes: 0

Views: 954

Answers (3)

amatellanes
amatellanes

Reputation: 3735

You can use onBackPressed():

@Override
public void onBackPressed() {
    showResults(0);
}

Upvotes: 1

Shaiful
Shaiful

Reputation: 5673

Just override the onKeyDown() method of Activity. You don't have to set a listener then.

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if(keyCode == KeyEvent.KEYCODE_BACK)
        {
            showResults(0);
            return true;
        }
        return super.onKeyDown(keyCode, event);
    }

Optionally you can also override onBackPressed() if your api level is >= 5.

Upvotes: 2

Blackbelt
Blackbelt

Reputation: 157457

For the Activity you should override onBackPressed which is invoked when you press the back button. OnKeyListener dispatches key events to the view. You find setOnKeyListener defined in the View class

Interface definition for a callback to be invoked when a hardware key event is dispatched to this view. The callback will be invoked before the key event is given to the view. This is only useful for hardware keyboards; a software input method has no obligation to trigger this listener.

Upvotes: 3

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