Why my ViewPager is so slow?

Why ViewPager is slow

• I'm using ViewPager to swipe between multiple images, but swiping between images is sluggish and not smooth although i only loaded few images. Here's my full code MainActivity.java public class MainActivity extends ActionBarActivity implements ActionBar.TabListener { public static SectionsPagerAdapter mSectionsPagerAdapter; public static ViewPager mViewPager; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager()); mViewPager = (ViewPager) findViewById(R.id.pager); mViewPager.setAdapter(mSectionsPagerAdapter); } public class SectionsPagerAdapter extends FragmentPagerAdapter { public SectionsPagerAdapter(FragmentManager fm) { super(fm); } @Override public Fragment getItem(int position) { Fragment fragment = null; Bundle args = new Bundle(); fragment = new Page(); args.putString(Page.ARG_SECTION_NUMBER, position); fragment.setArguments(args); return fragment; } public int getItemPosition(Object object) { Log.v("MBG", "getItemPosition"); return POSITION_NONE; } @Override public int getCount() { return 6; } } Page.java public class Page extends Fragment { public static final String ARG_SECTION_NUMBER = "section_number"; public Page() { } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View rootView = inflater.inflate(R.layout.activity_page, container, false); String index = getArguments().getString(ARG_SECTION_NUMBER); ImageView callImage = (ImageView) rootView.findViewById(R.id.imageView); int resID = getActivity().getResources().getIdentifier(index, "drawable", getActivity().getPackageName()); callImage.setImageResource(resID); return rootView; } MainActivity.xml <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" > <android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/pager" android:layout_marginTop="0dp" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".Prayers" /> </RelativeLayout> Page.xml <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="com.mahmoud.qaloun.Page"> <ImageView android:layout_width="match_parent" android:layout_height="match_parent" android:id="@+id/imageView" android:src="@drawable/a1" android:scaleType="fitXY" /> </RelativeLayout> But when i change this line of code int resID = getActivity().getResources().getIdentifier(index, "drawable", getActivity().getPackageName()); to this: int resID = getActivity().getResources().getIdentifier("1", "drawable", getActivity().getPackageName()); it works fine where "1" is an image stored in the resources folder "1.jpg"

• Answer:

  Put mViewPager.setOffscreenPageLimit(5); after mViewPager.setAdapter(); Replace 5 with the number of pages that are off screen, i.e. total number of pages minus 1. This will make your ViewPager smooth.