title: Android Studio getting "Must implement OnFragmentInteractionListener"
body: <p>I'm getting a throw that says "Must implement OnFragmentInteractionListener, and I already have it...</p>
  
  <p>I've looked at every question asked here, and no one helped me.</p>
  
  <p>Could anyone please help me?</p>
  
  <p>ERROR:</p>
  
  <pre><code>FATAL EXCEPTION: main
       Process: com.example.android.navigationdrawer, PID: 5916
       java.lang.RuntimeException: com.example.android.navigationdrawer.MainActivity@3aefae64 must implement OnFragmentInteractionListener
           at com.example.android.navigationdrawer.FragmentCamera.onAttach(FragmentCamera.java:83)
           at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1019)
           at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1248)
           at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:738)
           at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1613)
           at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:517)
           at android.os.Handler.handleCallback(Handler.java:739)
           at android.os.Handler.dispatchMessage(Handler.java:95)
           at android.os.Looper.loop(Looper.java:135)
           at android.app.ActivityThread.main(ActivityThread.java:5930)
           at java.lang.reflect.Method.invoke(Native Method)
           at java.lang.reflect.Method.invoke(Method.java:372)
           at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1405)
           at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1200)    
  </code></pre>
  
  <p>MAINACTIVITY (extending to OnFragmentInteractionListener)</p>
  
  <pre><code>package com.example.android.navigationdrawer;
  
  import android.content.Intent;
  import android.net.Uri;
  import android.os.Bundle;
  import android.support.design.widget.FloatingActionButton;
  import android.support.design.widget.NavigationView;
  import android.support.design.widget.Snackbar;
  import android.support.v4.app.Fragment;
  import android.support.v4.view.GravityCompat;
  import android.support.v4.widget.DrawerLayout;
  import android.support.v7.app.ActionBarDrawerToggle;
  import android.support.v7.app.AppCompatActivity;
  import android.support.v7.widget.Toolbar;
  import android.view.Menu;
  import android.view.MenuItem;
  import android.view.View;
  import android.widget.ImageView;
  import android.widget.Toast;
  
  public class MainActivity extends AppCompatActivity
          implements NavigationView.OnNavigationItemSelectedListener, FragmentCamera.OnFragmentInteractionListener {
  </code></pre>
  
  <p>MAINACTIVITY (FragmentCamera @Override)</p>
  
  <pre><code>@Override
  public void onFragmentInteraction(Uri uri) {
  
  
  }
  </code></pre>
  
  <p>MAINACTIVITY (ONCREATE)</p>
  
  <pre><code>@Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
      setSupportActionBar(toolbar);
  
      FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
      fab.setOnClickListener(new View.OnClickListener() {
          @Override
          public void onClick(View view) {
              Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                      .setAction("Action", null).show();
          }
      });
  
      DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
      ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
              this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
      drawer.setDrawerListener(toggle);
      toggle.syncState();
  
      NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
      navigationView.setNavigationItemSelectedListener(this);
  }
  </code></pre>
  
  <p>MAINACTIVITY (FRAGMENT TRANSACTION)</p>
  
  <pre><code>    boolean FragmentTransaction = false;
              Fragment fragment = null;
  
  
              //Camera
  
              if (id == R.id.nav_camera) {
  
                  Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");
                  startActivity(intent);
  
                  ImageView mImageView = (ImageView) findViewById(R.id.Galley1);
  
  
  
              //Galley
  
              } else if (id == R.id.nav_gallery) {
  
                  fragment = new FragmentCamera();
                  FragmentTransaction = true;
  }
  </code></pre>
  
  <p>...</p>
  
  <pre><code>        if(FragmentTransaction) {
              getSupportFragmentManager().beginTransaction()
                      .replace(R.id.drawer_layout, fragment)
                      .commit();
  
              item.setChecked(true);
              getSupportActionBar().setTitle(item.getTitle());
          }
  </code></pre>
  
  <p>FRAGMENTCAMERA</p>
  
  <pre><code>package com.example.android.navigationdrawer;
  
  import android.content.Context;
  import android.net.Uri;
  import android.os.Bundle;
  import android.support.v4.app.Fragment;
  import android.view.LayoutInflater;
  import android.view.View;
  import android.view.ViewGroup;
  
  
  /**
   * A simple {@link Fragment} subclass.
   * Activities that contain this fragment must implement the
   * {@link FragmentCamera.OnFragmentInteractionListener} interface
   * to handle interaction events.
   * Use the {@link FragmentCamera#newInstance} factory method to
   * create an instance of this fragment.
   */
  public class FragmentCamera extends Fragment {
      // TODO: Rename parameter arguments, choose names that match
      // the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
      private static final String ARG_PARAM1 = "param1";
      private static final String ARG_PARAM2 = "param2";
  
      // TODO: Rename and change types of parameters
      private String mParam1;
      private String mParam2;
  
      private OnFragmentInteractionListener mListener;
  
      public FragmentCamera() {
          // Required empty public constructor
      }
  
      /**
       * Use this factory method to create a new instance of
       * this fragment using the provided parameters.
       *
       * @param param1 Parameter 1.
       * @param param2 Parameter 2.
       * @return A new instance of fragment FragmentCamera.
       */
      // TODO: Rename and change types and number of parameters
      public static FragmentCamera newInstance(String param1, String param2) {
          FragmentCamera fragment = new FragmentCamera();
          Bundle args = new Bundle();
          args.putString(ARG_PARAM1, param1);
          args.putString(ARG_PARAM2, param2);
          fragment.setArguments(args);
          return fragment;
      }
  
      @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) {
          // Inflate the layout for this fragment
          return inflater.inflate(R.layout.fragment_camera, container, false);
      }
  
      // TODO: Rename method, update argument and hook method into UI event
      public void onButtonPressed(Uri uri) {
          if (mListener != null) {
              mListener.onFragmentInteraction(uri);
          }
      }
  
      @Override
      public void onAttach(Context context) {
          super.onAttach(context);
          if (context instanceof OnFragmentInteractionListener) {
              mListener = (OnFragmentInteractionListener) context;
          } else {
              throw new RuntimeException(context.toString()
                      + " must implement OnFragmentInteractionListener");
          }
      }
  
      @Override
      public void onDetach() {
          super.onDetach();
          mListener = null;
      }
  
      /**
       * This interface must be implemented by activities that contain this
       * fragment to allow an interaction in this fragment to be communicated
       * to the activity and potentially other fragments contained in that
       * activity.
       * &lt;p/&gt;
       * See the Android Training lesson &lt;a href=
       * "http://developer.android.com/training/basics/fragments/communicating.html"
       * &gt;Communicating with Other Fragments&lt;/a&gt; for more information.
       */
      public interface OnFragmentInteractionListener {
          // TODO: Update argument type and name
          void onFragmentInteraction(Uri uri);
      }
  }
  </code></pre>
  
  <p>If you need some more code, comment and I will add it!</p>