android - How to launch activity and show specific fragment

Question

I have a MainActivity that has several fragments which are added and then shown/hidden. This is because the MainActivity uses a NavigationDrawer. Clicking on items in the drawer causes different fragments to be added (if they do not exist), or shown/hidden if they do.

My question is, how can I launch my MainActivity via an intent from a different activity, and at the same time show a specific fragment?

Would I have to pass some extra to my MainActivity and then based on that data, add/show/hide the relevant fragment? Is there another way?

Answer 1

When you create your Intent, you can give it an extra that determines the fragment to load.

Intent i = new Intent(this, ActivityClass.class);
i.putExtra("frgToLoad", FRAGMENT_A);

// Now start your activity
startActivity(i);

Now, inside your activity check the extra and load the right Fragment:

OnCreate(){
    ...

    int intentFragment = getIntent().getExtras().getInt("frgToLoad");

    switch (intentFragment){
        case FRAGMENT_A:
            // Load corresponding fragment
            break;
        case FRAGMENT_B:
            // Load corresponding fragment
            break;
        case FRAGMENT_C:
            // Load corresponding fragment
            break;
    }
}