Question

Activity1 (not finish) can start Activity2 , Activity2 (not finish) can start Activity3.
And Activity2 and 3 can back to previous activity using

super.onBackPressed();
this.finish();

And I want to know how Activity3 back to Activity1(not refresh) directly and release the memory of Activity2?

Answer 1

Intent intent = new Intent(Activity3.this, Activity1.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);

This will make the Activity1 be at the top of the backstack, killing all Activities on top of it. Hope this helps.