Error calling method on fragment

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Error calling method on fragment

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#1 by (1 votes)
#2 by (1 votes)

1

My code below was to do a simple task by clicking on the switch to another screen, but it is giving an error:

Can not make a static reference to the non-static method callCast () from the type MainActivity

I already changed the chamaCadastro to static, but the error changes to:

Can not make a static reference to the non-static method setContentView (int) from the type ActionBarActivity

Follow my code:

MainActivity.java

package br.com.navegandoemtelas;

import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.os.Build;

public class MainActivity extends ActionBarActivity {

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

    if (savedInstanceState == null) {
        getSupportFragmentManager().beginTransaction()
                .add(R.id.container, new PlaceholderFragment())
                .commit();
    }
}

public void chamaMenuPrincipal(){
    setContentView(R.layout.activity_main);
}

public void chamaCadastro(){
    setContentView(R.layout.cadastros);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {

    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}

/**
 * A placeholder fragment containing a simple view.
 */

public static class PlaceholderFragment extends Fragment {

    Button btCadastro;

    public PlaceholderFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_main, container, false);

        btCadastro = (Button) rootView.findViewById(R.id.btCadastrar);
        btCadastro.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                chamaCadastro();                    
            }
        });

        return rootView;
    }
}

}

java android android-fragment

asked by anonymous 21.03.2014 / 21:04

2 answers

1

In theory and practice the best thing to do is this:

Change the scope of your method by making it static:

public static void chamaCadastro(){
    setContentView(R.layout.cadastros);
}

Create a separate file named PlaceholderFragment.java and paste the following code there, changing the scope of the class to public class :

public class PlaceholderFragment extends Fragment {

    Button btCadastro;

    public PlaceholderFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_main, container, false);

        btCadastro = (Button) rootView.findViewById(R.id.btCadastrar);
        btCadastro.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                MainActivity.chamaCadastro();                    
            }
        });

        return rootView;
    }
}

Import the MainActivity into PlaceholderFragment.java to be able to access its methods.

You can now access the MainActivity.chamaCadastro() method as seen in the full code above:

        @Override
        public void onClick(View v) {
            MainActivity.chamaCadastro();                    
        }

Note: Although I do not recommend changing layout in an activity, it is much better to create an Activity for each operation (registration / editing) etc.

21.03.2014 / 21:50

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score 1 · Accepted Answer

Add this to the MainActivity class:

public static MainActivity context;

In the constructor, add the line:

context = this;

And in the "call", use:

context.chamaCadastro();

True. Fragments within a class should be static.