views:

85

answers:

3

Hi!

I want to do something simple on android app. How is it possible to go back to a previous activity.

What code do I need to go back to previous activity

A: 

Are you wanting to take control of the back button behavior? You can override the back button (to go to a specific activity) via one of two methods.

For Android 1.6 and below:

@Override
public boolean onKeyDown(int keyCode, KeyEvent event)  {
    if (keyCode == KeyEvent.KEYCODE_BACK && event.getRepeatCount() == 0) {
        // do something on back.
        return true;
    }

    return super.onKeyDown(keyCode, event);
}

Or if you are only supporting Android 2.0 or greater:

@Override
public void onBackPressed() {
    // do something on back.
    return;
}

For more details: http://android-developers.blogspot.com/2009/12/back-and-other-hard-keys-three-stories.html

Bryan Denny
A: 

Try Activity#finish(). This is more or less what the back button does by default.

adamp
+1  A: 

Android activities are stored in the activity stack. Going back to a previous activity could mean two things.

  1. You opened the new activity from another activity with startActivityForResult. In that case you can just call the finishActivity() function from your code and it'll take you back to the previous activity.

  2. Keep track of the activity stack. Whenever you start a new activity with an intent you can specify an intent flag like FLAG_ACTIVITY_REORDER_TO_FRONT or FLAG_ACTIVITY_PREVIOUS_IS_TOP. You can use this to shuffle between the activities in your application. Haven't used them much though. Have a look at the flags here: http://developer.android.com/reference/android/content/Intent.html

Abhinav