Make back button working in action bar in Android.

Recently I was trying to use working back button on my one of the project, but whatever I was done previously was not working. It was a crash every time with error message -

I am newbie to Android, but I was done back activity few day back but after updating my Android Studios and APIs nothing was working. I was also uses  inflated menu in my project, and debugger always stuck in onOptionsItemSelected(MenuItem item) method which I was used for option menu. I also tried many unsuccessful lines of code. Finally I got this solution for my problem -

1 .  In  onCreate(Bundle savedInstanceState) method use -

getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setDisplayShowHomeEnabled(true);

2 .  Override methos in your activity class

@Overridepublic boolean onSupportNavigateUp() {
    onBackPressed();
    return true;
}



3 . In onOptionsItemSelected(MenuItem item) method use  -

switch (item.getItemId()) {  
       case android.R.id.home:
        Intent i = new Intent(this, Your_Parent_Activity.class);
        intent.addFlags(i.FLAG_ACTIVITY_CLEAR_TOP);
        startActivity(i);
        return true;
}