Fragments in android?

Question

Java

There is a code:

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_re);
        fragmentManager = getFragmentManager();
        if(getIntent().getExtras().get(keyMessage).equals("R")) registration();
        else
        if(getIntent().getExtras().get(keyMessage).equals("E")) enter();
        else Toast.makeText(ReActivity.this, "Error01 Please restart the application", Toast.LENGTH_SHORT).show();
    }

In which, depending on what the past activity passed, the method is called.
And then the method itself:

private void enter(){
        EnterFragment entFragment = new EnterFragment();
        fragmentManager.beginTransaction()
                .add(R.id.fragmentRE,entFragment)
                .commit();
        entFragment.getView().findViewById(R.id.button).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
            }
        });
    }

The problem is nullPointerExpection where we want to get a listener from the button
(The button itself is present on the fragment with the same id as in the code)
Tell me where I made a mistake and how to fix it?

Answer 1

Layout at that moment is simply not loaded yet, you need to do it in the Fragment itself, in onCreateView, after inflate.