NullPointerException on FragmentActivity.onBackPressed() - nullpointerexception

Question

I have a problem on up back icon toolbar, when i click twice to go back app crash on nullpointer exception recalling the error on my getActivity().onBackPressed();
this is the fragment:
package com.example.android.evilsecretgallery;
import android.graphics.Bitmap;
import android.os.Build;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.transition.TransitionInflater;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import com.bumptech.glide.Glide;
import com.bumptech.glide.request.target.SimpleTarget;
import com.bumptech.glide.request.transition.Transition;
import com.github.chrisbanes.photoview.PhotoView;
public class ImageDetailFragment extends Fragment {
private static final String EXTRA_IMAGE = "image_item";
private static final String EXTRA_TRANSITION_NAME = "transition_name";
public ImageDetailFragment() {
// Required empty public constructor
}
public static ImageDetailFragment newInstance(ImageModel image, String transitionName) {
ImageDetailFragment fragment = new ImageDetailFragment();
Bundle args = new Bundle();
args.putParcelable(EXTRA_IMAGE, image);
args.putString(EXTRA_TRANSITION_NAME, transitionName);
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
postponeEnterTransition();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
setSharedElementEnterTransition(TransitionInflater.from(getContext()).inflateTransition(android.R.transition.move));
}
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_image_detail, container, false);
Toolbar toolbar = getActivity().findViewById(R.id.toolbar);
toolbar.setTitle(" ES ");
toolbar.setTitleTextAppearance(getActivity(), R.style.EvilTextAppearance);
toolbar.setNavigationOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
getActivity().onBackPressed();
}
});
return rootView;
}
#Override
public void onViewCreated(View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
final ImageModel image = getArguments().getParcelable(EXTRA_IMAGE);
String transitionName = getArguments().getString(EXTRA_TRANSITION_NAME);
final PhotoView imageView = view.findViewById(R.id.detail_image);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
imageView.setTransitionName(transitionName);
}
Glide.with(getActivity())
.asBitmap()
.load(image.getUrl())
.into(new SimpleTarget<Bitmap>() {
#Override
public void onResourceReady(#NonNull Bitmap resource, #Nullable Transition<? super Bitmap> transition) {
startPostponedEnterTransition();
imageView.setImageBitmap(resource);
}
});
}
}
that go back in this activity:
package com.example.android.evilsecretgallery;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.Toolbar;
import android.view.MenuItem;
public class PagesActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_pages);
Toolbar toolbar = findViewById(R.id.toolbar);
toolbar.setTitle(" ES ");
toolbar.setTitleTextAppearance(this, R.style.EvilTextAppearance);
setSupportActionBar(toolbar);
if (getSupportActionBar()!=null){
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setDisplayShowHomeEnabled(true);
}
getSupportFragmentManager()
.beginTransaction()
.add(R.id.content, RecyclerViewFragment.newInstance())
.commit();
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId()==android.R.id.home)
finish();
return super.onOptionsItemSelected(item);
}
}
then if I go back again to this activity below it gives me the error:
package com.example.android.evilsecretgallery;
import android.content.Intent;
import android.net.Uri;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
ImageView cover;
Toolbar toolbar;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
toolbar = findViewById(R.id.toolbar);
toolbar.setTitle(" ES ");
toolbar.setTitleTextAppearance(this, R.style.EvilTextAppearance);
setSupportActionBar(toolbar);
cover = findViewById(R.id.cover_id);
cover.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
// Create a new intent to open the PagesActivity
Intent intent = new Intent(MainActivity.this, PagesActivity.class);
// Start the new activity
startActivity(intent);
}
});
Button siteButton = findViewById(R.id.site_button);
siteButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
String url = "http://www.evilsecret.it";
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setData(Uri.parse(url));
startActivity(intent);
}
});
}
}
I have made some experiment and if i go back from pages activity it has no problem. I have to use different method in the fragment?

Answer 1

try clean and rebuild your project
It worked for me.