Android : Return to previous fragment on back press

Question

I have implemented Navigation Drawer which is a subclass of Activity. I have many fragments in my application. My question goes here

Imagine there are 3 fragments :

Answer 1

Update your Activity#onBackPressed() method to:

@Override
public void onBackPressed() {
    if (getFragmentManager().getBackStackEntryCount() > 0) {
        getFragmentManager().popBackStack();
    } else {
        super.onBackPressed();
    }
}

The reason your implementation doesn't work is because the method FragmentManager#popBackStack() is asynchronous and does not happen right after it is called.

From the documentation:

This function is asynchronous -- it enqueues the request to pop, but the action will not be performed until the application returns to its event loop.

Reference: http://developer.android.com/reference/android/app/FragmentManager.html#popBackStack(java.lang.String,%20int)