title: Navigate from Android Activity to Fragment
body: <p>I'm currently using the Jetpack Navigation Controller to manage navigation throughout my app. However I've encountered a situation that seems rather simple but I cannot find a solution.</p>
  
  <p>From my main nav drawer I'm able to navigate to an activity (Activity2) that does not contain any fragments. The main activity (MainActivity) constructs the nav controller and sets up the navigation. </p>
  
  <p>Within the activity that does not contain any fragments, I would like to navigate to a fragment in another part of the application, however I've encountered several probems depending upon the approach. </p>
  
  <p>I first tried a traditional approach:</p>
  
  <pre><code>FragmentManager fm = getSupportFragmentManager();
  MyFragment myFragment = new MyFragment();
  fm.beginTransaction().replace(?????????, loginFragment).commit();
  </code></pre>
  
  <p>In this situation what am I to include for ?????????.</p>
  
  <p>I also tried to use a NavController in Activity2 onCreate:</p>
  
  <pre><code>NavController navController = Navigation.findNavController(??????, R.id.nav_myFragment);
  </code></pre>
  
  <p>again in this situation what would I include in ??????.</p>