How can I use the Android back button to move back within my app instead of closing my app?

Question

My app has three activities, A, B and C. I am moving from A to B through an OK button, and I want to move back from B to A by using the default back button of Android devices. W

Answer 1

why start your activity for result ? when you press the backbutton, the result is set to RESULT_CANCELED form the B activity, so it crashes if you don't handle the resultcode...

you can handle the backpress like this

private static final int NONE = -1;

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {

    if (keyCode == KeyEvent.KEYCODE_BACK) {

   setResult(NONE, intent);
        finish();
    return super.onKeyDown(keyCode, event);
}