Mainactivity recognizes methods from external classes

Question

And everyone, I’m starting to program with Android Studio, but I have a problem. I created a class in the same mainactivity package, and I was able to instill that class, but I can’t use its Methods. Mainactivity is not recognizing these methods.

Follows Code of the Class:

package com.example.myapplication;

public class Casa {

    public void AbrirPorta(){
        System.out.println("Porta Aberta");
    }
}

Follow Mainactivity Code:

package com.example.myapplication;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    Casa C = new Casa();
}

Answer 1

Good night, Wesley!

Simply call your method within another, that way

public class MainActivity extends AppCompatActivity {
    Casa c = new Casa(); // Mudei de posição apenas por questões didáticas

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Chame aqui ou dentro de outro método
        c.seuMetodo();
    }
}

In class internal space, you can only declare properties/parameters, methods and instantiating objects [as you did], but you cannot call methods.