Problem to stop import class from EditText

I'm trying to import the EditText class and I can not, what can it be?

import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.EditText;
import android.widget.ArrayAdapter;
import android.widget.ImageButton;
import android.widget.RadioButton;
import android.widget.Spinner;

public class TelaCadastro extends AppCompatActivity{

Usuario usuario = new Usuario();
private EditText tfNome;
private EditText tfIdade;
private EditText tfAltura;
private EditText tfPeso;
private EditText tfLogin;
private EditText tfSenha;
private RadioButton rbMasculino;
private RadioButton rbFeminino;
private Spinner spinner;
ImageButton next;

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

    //Spinner (combo box)
    spinner = (Spinner) findViewById(R.id.spinner);
    ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this,
            R.array.planets_array,
            android.R.layout.simple_spinner_item);
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    spinner.setAdapter(adapter);

    tfNome = (EditText) findViewById(R.id.tf_nome);
    tfIdade = (EditText) findViewById(R.id.tf_idade);
    tfAltura = (EditText) findViewById(R.id.tf_altura);
    tfPeso = (EditText) findViewById(R.id.tf_peso);
    tfLogin = (EditText) findViewById(R.id.tf_login);
    tfSenha = (EditText) findViewById(R.id.tf_senha);
}

no import android.widget.EditText; the error "Can not resolve symbol 'EditText'"