Develop Reference

app crashes while opening new fragment inside viewpager

I'm trying to open a new fragment in viewpager's fragment using this as example. But I'm getting this error of IndexOutOfBoundsException in the line tabLayout.getTabAt(0).setIcon(tabIcons[0]);. I pasted the logcate here. Can any one tell me how to solve this as I need tablayout with my viewpager while the example didn't had one?
public class FirstFragment extends Fragment {
private static final String TAG = "FirstFragment";
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.first_fragment, container, false);
Button btn = (Button) view.findViewById(R.id.btn);
btn.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
FragmentTransaction trans = getFragmentManager()
.beginTransaction();
/*
* IMPORTANT: We use the "root frame" defined in
* "root_fragment.xml" as the reference to replace fragment
*/
trans.replace(R.id.root_frame, new SecondFragment());
/*
* IMPORTANT: The following lines allow us to add the fragment
* to the stack and return to it later, by pressing back
*/
trans.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
trans.addToBackStack(null);
trans.commit();
}
});
return view;
}
}
First tab:
public class RootFragment extends Fragment {
private static final String TAG = "RootFragment";
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
/* Inflate the layout for this fragment */
View view = inflater.inflate(R.layout.root_fragment, container, false);
FragmentTransaction transaction = getFragmentManager()
.beginTransaction();
/*
* When this container fragment is created, we fill it with our first
* "real" fragment
*/
transaction.replace(R.id.root_frame, new FirstFragment());
transaction.commit();
return view;
}
}
Main Activity:
public class MainActivity extends AppCompatActivity {
// For this example, only two pages
static final int NUM_ITEMS = 2;
private TabLayout tabLayout;
private ViewPager mPager;
private int[] tabIcons = {
R.drawable.facebook,
R.drawable.twitter
};
SlidePagerAdapter mPagerAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
/* Instantiate a ViewPager and a PagerAdapter. */
tabLayout=(TabLayout)findViewById(R.id.tabs);
mPager = (ViewPager) findViewById(R.id.viewpager);
mPagerAdapter = new SlidePagerAdapter(getSupportFragmentManager());
mPager.setAdapter(mPagerAdapter);
setupTabIcons();
}
private void setupTabIcons() {
tabLayout.getTabAt(0).setIcon(tabIcons[0]);
tabLayout.getTabAt(1).setIcon(tabIcons[1]);
}
/* PagerAdapter class */
public class SlidePagerAdapter extends FragmentPagerAdapter {
public SlidePagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
/*
* IMPORTANT: This is the point. We create a RootFragment acting as
* a container for other fragments
*/
if (position == 0)
return new RootFragment();
else
return new StaticFragment();
}
#Override
public int getCount() {
return NUM_ITEMS;
}
}
}

use below function
private void setupTabIcons() {
tabLayout.addTab(tabLayout.newTab().setIcon(tabIcons[0]));
tabLayout.addTab(tabLayout.newTab().setIcon(tabIcons[1]));
}
you have not added any tab to your tabLayout, so you get IndexOutOfBoundsException

Can't swipe to next item inside my detail activity after implementing viewpager

I am trying to swipe item(from listview) in my detail activity using viewpager.
I have 20 items in my listview (data parsed from json) Instead of swiping the next/previous item , It's only the same item that I swipe (20 times).
here is my DetailActivity.
public class DetailsActivity extends FragmentActivity {
Article feed;
int pos;
private DescAdapter adapter;
private ViewPager pager;
...
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.item_details);
pos = getIntent().getExtras().getInt("pos");
adapter = new DescAdapter(getSupportFragmentManager());
pager = (ViewPager) findViewById(R.id.pager);
pager.setAdapter(adapter);
pager.setCurrentItem(pos);
}
public class DescAdapter extends FragmentStatePagerAdapter {
public DescAdapter(FragmentManager fm) {
super(fm);
}
#Override
public int getCount() {
return 20;
}
public Fragment getItem(int position) {
return DetailFragment.newInstance(position);
}
}
And my detailFragment
public class DetailFragment extends Fragment {
static DetailFragment newInstance(int position) {
DetailFragment f = new DetailFragment();
return f;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.detail_fragment, container, false);
String displaytitle= getActivity().getIntent().getStringExtra("title");
TextView titleF = (TextView)view.findViewById(R.id.title);
titleF.setText(displaytitle);
...
return view;
}
What am I doing wrong?

You are not using the correct argument:
You send the argument "pos2" but you retrieve the argument "title".
#Override
public Fragment getItem(int position) {
DetailFragment frag = new DetailFragment();
Bundle bundle = new Bundle();
bundle.putInt("fPos",position);
frag.setArguments(bundle);
return frag;
}

error on calling getSupportFragmentManager() from activity

I am trying to implement Swipe view using fragment.
But its very important for me to extend simple activity rather than fragment activity.
I am getting error on getSupportFragmentManager() in the code written below:
public class CollectionDemoActivity extends Activity {
DemoCollectionPagerAdapter mDemoCollectionPagerAdapter;
ViewPager mViewPager;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_collection_demo);
mDemoCollectionPagerAdapter = new DemoCollectionPagerAdapter(getSupportFragmentManager());
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mDemoCollectionPagerAdapter);
}
public static class DemoCollectionPagerAdapter extends FragmentStatePagerAdapter {
public DemoCollectionPagerAdapter(FragmentManager fm) {
super(fm);
//int x=10;
}
#Override
public Fragment getItem(int i) {
Fragment fragment = new DemoObjectFragment();
Bundle args = new Bundle();
args.putInt(DemoObjectFragment.ARG_OBJECT, i + 10);
fragment.setArguments(args);
return fragment;
}
#Override
public int getCount() {
// For this contrived example, we have a 100-object collection.
return 100;
}
#Override
public CharSequence getPageTitle(int position) {
return "OBJECT " + (position + 1);
}
}
public static class DemoObjectFragment extends Fragment {
public static final String ARG_OBJECT = "object";
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_collection_object, container, false);
Bundle args = getArguments();
((TextView) rootView.findViewById(android.R.id.text1)).setText(
Integer.toString(args.getInt(ARG_OBJECT)));
return rootView;
}
}
}

The error is pretty self-explanatory. getSupportFragmentManager() is only defined for the FragmentActivity class. No matter how much you want or need to call that method, it simply doesn't exist for plain Activities.
See also: Difference between Activity and FragmentActivity and Difference between Fragment and FragmentActivity

Fragment member variables getting null when accessed in onPageSelected()

I'm using FragmentPagerAdapter with FragmentActivity to create swipe-able Fragments.
My first fragment in that pagerAdapter look like this.
public class MySummaryFragment extends CommonFragment implements OnPageChangeListener
{
private Context mContext;
private View mMyView;
LinearLayout mDetailLayout;
TextView mDateTxtView;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
System.out.println("onCreateView() Market summary");
mMyView = inflater.inflate(R.layout.my_page_summary_fragment_layout, container,false);
mDetailLayout = (LinearLayout)mMyView.findViewById(R.id.SummaryDetailLayout);
mDateTxtView = (TextView) mMyView.findViewById(R.id.txtDate);
Account_Id = AccountDetails.getInstance(mContext).getClientCodes().get(0);
sendRequest(Account_Id);
return mMyView;
}
#Override
public void onPageSelected(int arg0) {
System.out.println("inside onPageScrollStateChanged()");
System.out.println("mMyView is null ? = "+(mMyView==null));
mDateTxtView = (TextView) mMyView.findViewById(R.id.txtMarketSummaryDate);
Account_Id = AccountDetails.getInstance(mContext).getClientCodes().get(0);
mDateTxtView.setText("");
sendRequest(Account_Id);
}
}
The problem here is I'm getting NullPointerException when swipe-out to 5-6 fragments and swiping back to first fragment.
When I try to debug, I found that
mMyView is null ? = true
Why so?
Please help me.
Here is my Fragment contains the FragmentPagerAdapter,
public class MyPageDetailViewFragment extends CommonFragment {
private View mView;
Context mContext;
OnPageChangeListener pageChangeListener;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
mView = inflater.inflate(R.layout.my_page_fragments, null);
mContext = getActivity();
setHasOptionsMenu(false);
setupSearchBarComponent();
PagerTabStrip pagerTabStrip = (PagerTabStrip)mView. findViewById(R.id.pager_title_strip);
pagerTabStrip.setDrawFullUnderline(true);
pagerTabStrip.setTabIndicatorColor(Color.BLACK);
/** Getting a reference to the ViewPager defined the layout file */
ViewPager pager = (ViewPager) mView.findViewById(R.id.pager);
/** Getting fragment manager */
FragmentManager fm = ((HomeScreenActivity)mContext).getSupportFragmentManager();
/** Instantiating FragmentPagerAdapter */
final MyFragmentPagerAdapter pagerAdapter = new MyFragmentPagerAdapter(fm);
pager.setAdapter(pagerAdapter);
pager.setCurrentItem(0);
pageChangeListener = new OnPageChangeListener() {
#Override
public void onPageSelected(int selectedIndex) {
System.out.println("selectedIndex = "+selectedIndex);
Object page = pagerAdapter.getItem(selectedIndex);
if( page instanceof OnPageChangeListener){
((OnPageChangeListener) page).onPageSelected(selectedIndex);
}
}
#Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
#Override
public void onPageScrollStateChanged(int arg0) {
}
};
pager.setOnPageChangeListener(pageChangeListener);
return mView;
// return super.onCreateView(inflater, container, savedInstanceState);
}
And here is my implementation MyFragmentPagerAdapter,
public class MyFragmentPagerAdapter extends FragmentPagerAdapter {
/** Constructor of the class */
public MyFragmentPagerAdapter(FragmentManager fm) {
super(fm);
}
/** This method will be invoked when a page is requested to create */
#Override
public Fragment getItem(int index) {
System.out.println("getItem = "+index);
Bundle data = new Bundle();
data.putInt("current_page", index + 1);
CommonFragment fragment = getFragment(index);
fragment.setArguments(data);
return fragment;
}
public CommonFragment getFragment(int index) {
CommonFragment fragment = null;
if(fragment == null){
if(index == 0){
fragment = new MySummaryFragment();
}else if(index == 1){
fragment = new FragmentOne();
}else if(index == 4){
fragment = new FragmentFour();
}else if(index == 5){
fragment = new FragmentFive();
}else{
fragment = new MyFragment();
}
}
return fragment;
}
/** Returns the number of pages */
#Override
public int getCount() {
return titles.length;
}
#Override
public CharSequence getPageTitle(int position) {
return titles[position];
}
}

pagerAdapter.getItem(selectedIndex) actually creates a new instance of the fragment.
See this answer: https://stackoverflow.com/a/23843743/1271907
You have to keep a reference to the actual fragment.

It looks like you are calling the wrong method on the inflater.
Try to change this line:
mView = inflater.inflate(R.layout.my_page_fragments, null);
to:
mView = inflater.inflate(R.layout.my_page_fragments,container, null);

ViewPager contain separate activity for each page

Any idea on how to set separate activity on each page on ViewPager. I try compatibility package by using FragmentActivity, but on the sample given, it just one type which is ListFragment.
The code I copied from sample of compatibility v4:
public class ViewPagerListActivity extends FragmentActivity {
static final int NUM_ITEMS = 10;
MyAdapter mAdapter;
ViewPager mPager;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_pager);
mAdapter = new MyAdapter(getSupportFragmentManager());
mPager = (ViewPager)findViewById(R.id.pager);
mPager.setAdapter(mAdapter);
// Watch for button clicks.
Button button = (Button)findViewById(R.id.goto_first);
button.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
mPager.setCurrentItem(0);
}
});
button = (Button)findViewById(R.id.goto_last);
button.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
mPager.setCurrentItem(NUM_ITEMS-1);
}
});
}
public static class MyAdapter extends FragmentPagerAdapter {
public MyAdapter(FragmentManager fm) {
super(fm);
}
#Override
public int getCount() {
return NUM_ITEMS;
}
#Override
public Fragment getItem(int position) {
return ArrayListFragment.newInstance(position);
}
}
public static class ArrayListFragment extends ListFragment {
int mNum;
/**
* Create a new instance of CountingFragment, providing "num"
* as an argument.
*/
static ArrayListFragment newInstance(int num) {
ArrayListFragment f = new ArrayListFragment();
// Supply num input as an argument.
Bundle args = new Bundle();
args.putInt("num", num);
f.setArguments(args);
return f;
}
/**
* When creating, retrieve this instance's number from its arguments.
*/
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mNum = getArguments() != null ? getArguments().getInt("num") : 1;
}
/**
* The Fragment's UI is just a simple text view showing its
* instance number.
*/
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_pager_list, container, false);
View tv = v.findViewById(R.id.text);
((TextView)tv).setText("Fragment #" + mNum);
return v;
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
setListAdapter(new ArrayAdapter<String>(getActivity(),
android.R.layout.simple_list_item_1, Cheeses.sCheeseStrings));
}
#Override
public void onListItemClick(ListView l, View v, int position, long id) {
Log.i("FragmentList", "Item clicked: " + id);
}
}
}
The following execution:
I would like to put activity or view with specific UI and process on each ViewPager, not just one type ListView like on above code sample. for example page 1 is map information; page 2 is combination TextView, EditView and button, Page 3 is Gallery; and so on. Any idea to implement it? or is there any tutorial for this?