How does NavUtils.navigateUpFromSameTask work?

问题

please what is actuall behavior of this method? I thought that when bind this method call to my actionbar back button and also set the homepageactivity name in Manifest.xml, it should be then opened after the click in the button - regardless of the current task stack.. For example, when I open my Activity from widget, the parent Activity is not in BackStack - this is what I want to solve..I know I can somehow build my own taskstack, but I just thought, that this should be prebaked solution, shouldn't be? Right now it sends me back to the homescreen.. This is where I call it..the code is located in onOptionsItemSelected

 case android.R.id.home: 
            NavUtils.navigateUpFromSameTask(this);
            //finish();
            return true;

来源：https://stackoverflow.com/questions/18941355/how-does-navutils-navigateupfromsametask-work