CrimePagerActivity.java
import android.content.Context; import android.content.Intent; import android.os.Bundle; import android.support.v4.app.Fragment; import android.support.v4.app.FragmentManager; import android.support.v4.app.FragmentStatePagerAdapter; import android.support.v4.view.ViewPager; import android.support.v7.app.AppCompatActivity; import java.util.List; import java.util.UUID; public class CrimePagerActivity extends AppCompatActivity { private static final String EXTRA_CRIME_ID = "com.bignerdranch.android.criminalintent.crime_id"; private ViewPager mViewPager; private List<Crime> mCrimes; public static Intent newIntent(Context packageContext, UUID crimeId) { Intent intent = new Intent(packageContext, CrimePagerActivity.class); intent.putExtra(EXTRA_CRIME_ID, crimeId); return intent; } @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_crime_pager); UUID crimeId = (UUID) getIntent() .getSerializableExtra(EXTRA_CRIME_ID); mViewPager = (ViewPager) findViewById(R.id.crime_view_pager); mCrimes = CrimeLab.get(this).getCrimes(); FragmentManager fragmentManager = getSupportFragmentManager(); mViewPager.setAdapter(new FragmentStatePagerAdapter(fragmentManager) { @Override public Fragment getItem(int position) { Crime crime = mCrimes.get(position); return CrimeFragment.newInstance(crime.getId()); } @Override public int getCount() { return mCrimes.size(); } }); for (int i = 0; i < mCrimes.size(); i++) { if (mCrimes.get(i).getId().equals(crimeId)) { mViewPager.setCurrentItem(i); break; } } } }