带片段的FindViewbyID

Question

I have this problem with fragments.. I wanted to add a drawer menu in my app and than work with fragments. I have this code, and when i putted the fragments "findviewbyid" didnt works more. Someone can help me?

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.fragment_contact);



    final EditText nome        = (EditText) findViewById(R.id.nome);
    final EditText citta       = (EditText) findViewById(R.id.citta);
    final EditText numero      = (EditText) findViewById(R.id.numero);
    final EditText email       = (EditText) findViewById(R.id.email);
    final EditText oggetto     = (EditText) findViewById(R.id.oggetto);
    final EditText messaggio    = (EditText) findViewById(R.id.messaggio);



    Button email = (Button) findViewById(R.id.post_message);
    email.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            String name      = nome.getText().toString();
            String citta     = citta.getText().toString();
            String numero    = numero.getText().toString();
            String email     = mail.getText().toString();
            String oggetto   = oggetto.getText().toString();
            String messaggio   = messaggio.getText().toString();
            if (TextUtils.isEmpty(nome)){
                nome.setError("Inserisci il Tuo Nome");
                nome.requestFocus();
                return;
            }

thank you and sorry for my english

Answer 1

The Fragment is not a Activity which means you can not use activity methods or it's lifecycle. This means you cant find views in the onCreate() method of a Fragment and you can not use findViewById on it either.

This is the Android lifecycle https://stackoverflow.com/a/36340059/4467208

and to adjust your code according to that, move your findViews into onCreateView() like this

public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragmentLayout, container, false);
    nome = (EditText) view.findViewById(R.id.nome);
    return view;
}

And so on.