java - studio - ERROR: debe implementar OnFragmentInteractionListener

comunicar activity con fragment

Question

Se trata de un error que dice que debo implementar OnFragmentInteractionListener, pero que yo sepa, lo estoy implementando correctamente ... Cualquier ayuda sería muy apreciada.

Actividad principal

 import android.app.Activity;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.os.Bundle;
public class MainActivity extends Activity implements NavFragment.OnFragmentInteractionListener, ContentFragment.OnFragmentInteractionListener{
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.add(R.id.nav, new NavFragment());
fragmentTransaction.commit();
fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.add(R.id.content, new ContentFragment());
fragmentTransaction.commit();
}
@Override
public void onNavFragmentInteraction(String string) {
Bundle args = new Bundle();
args.putString("string", string);
ContentFragment content = new ContentFragment();
content.setArguments(args);
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();
}
@Override
public void onContentFragmentInteraction(String string){
}
}

NavFragment

import android.app.Activity;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
public class NavFragment extends Fragment implements View.OnClickListener {
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
private String mParam1;
private String mParam2;
private Button button;
private OnFragmentInteractionListener mListener;
public static NavFragment newInstance(String param1, String param2) {
NavFragment fragment = new NavFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
public NavFragment() {
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_nav, container, false);
button = (Button) v.findViewById(R.id.submit);
button.setOnClickListener(this);
return v;
}
public void onButtonPressed(String string) {
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mListener = (OnFragmentInteractionListener) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement OnFragmentInteractionListener");
}
}
@Override
public void onDetach() {
super.onDetach();
mListener = null;
}
@Override
public void onClick(View v) {
String string = ((EditText) v.findViewById(R.id.gridSize)).toString();
mListener.onNavFragmentInteraction(string);
}
public interface OnFragmentInteractionListener {
public void onNavFragmentInteraction(String string);
}
}

ContentFragment

import android.app.Activity;
import android.app.Fragment;
import android.net.Uri;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.GridView;
public class ContentFragment extends Fragment {
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
private String mParam1;
private String mParam2;
private OnFragmentInteractionListener mListener;
public static ContentFragment newInstance(String param1, String param2) {
ContentFragment fragment = new ContentFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
public ContentFragment() {
// Required empty public constructor
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_content_fragmet, container, false);
String string = "1";
if (getArguments() != null) {
Bundle args = getArguments();
string = (String) args.get("string");
}
GridView gridView = (GridView) v.findViewById(R.id.gridview);
gridView.setNumColumns(Integer.parseInt(string));
gridView.setAdapter(new GridAdapter(this, Integer.parseInt(string)));
return v;
}
public void onButtonPressed(Uri uri) {
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mListener = (OnFragmentInteractionListener) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement OnFragmentInteractionListener");
}
}
@Override
public void onDetach() {
super.onDetach();
mListener = null;
}
public interface OnFragmentInteractionListener {
public void onContentFragmentInteraction(String string);
}
}

error

03-02 18:46:47.254 1958-1958/com.peterchappy.lab5 E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.peterchappy.lab5, PID: 1958
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.peterchappy.lab5/com.peterchappy.lab5.MainActivity}: java.lang.ClassCastException: com.peterchappy.lab5.MainActivity@2298f3ca must implement OnFragmentInteractionListener
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
at android.app.ActivityThread.access$800(ActivityThread.java:144)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
Caused by: java.lang.ClassCastException: com.peterchappy.lab5.MainActivity@2298f3ca must implement OnFragmentInteractionListener
at com.peterchappy.lab5.ContentFragmet.onAttach(ContentFragmet.java:83)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:853)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1067)
at android.app.BackStackRecord.run(BackStackRecord.java:833)
at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1452)
at android.app.Activity.performStart(Activity.java:5948)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2261)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
            at android.app.ActivityThread.access$800(ActivityThread.java:144)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5221)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)

Answer 1

Las interfaces OnFragmentInteractionListener en ambos Fragment contienen un método con la misma firma, y MainActivity está implementando un método para tratar de cubrir ambas interfaces.

Cambie la firma de uno o ambos métodos, luego implemente ambos métodos en MainActivity . Por ejemplo:

NavFragment

 public interface OnFragmentInteractionListener {
public void onNavFragmentInteraction(String string);
}

ContentFragment

 public interface OnFragmentInteractionListener {
public void onContentFragmentInteraction(String string);
}

Actividad principal

 @Override
public void onNavFragmentInteraction(String string) {
// Do stuff
}
@Override
public void onContentFragmentInteraction(String string) {
// Do different stuff
}