尽管存在片段事务的commit（），但未调用onAttach（）-方法

Question

I am wondering, how I can figure out, why my onAttach-method is not getting called. There is a commit of the fragment transaction and a corresponding replace. My log-Messages and my debug steps are telling me, that the onAttach() method of my QuotesFragment class never got triggered.

Here is my forward procedure in my MainActivity-class:

private void forwardToQuotesFragment(){
    FragmentTransaction ft = getFragmentManager().beginTransaction();
    ft.replace(R.id.container, quotesFragment, QuotesFragment.QUOTES_FRAGMENT_TAG);
    ft.commit();
    // onAttach()-method of QuotesFragment is not getting called - why?
}

Answer 1

I found the problem. As I mentioned in my prior comment, the reason for my issue was that on my cell phone Android 5.0.2 was installed and my app was created for Android 6.0 upwards.

Furthermore I used the android.app.*-classes. Now I changed those classes to the corresponding android-support-library-classes. That means my MainActivity extends from AppCompatActivity and my fragments from android.support.v4.app.Fragment. There is a need to update the fragment transaction procedure a little bit, as you can see below:

private void forwardToQuotesFragment(){
    android.support.v4.app.FragmentManager fm = getSupportFragmentManager();
    android.support.v4.app.FragmentTransaction ft = fm.beginTransaction();
    ft.replace(R.id.container, quotesFragment);
    ft.commit();
}