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keep previously loaded fragment instance when tab changes instead of creating new one in android

I have a tab swiped layout which includes four tabs each of which have their own layout and fragment, in my main activity layout a viewpager takes part for changing tabs. specific view(tab) loads when app starts up and the others will be loaded when the tab changes. my problem is when I nevigate to the third or forth tab (not the second tab) a new instance of it's corresponding fragment will be created instead of loading previously created fragment (the expected behavior that only occur for the second tab).When I navigate to the second tab (SecondPageFragment()) and again come back to first tab it works correct and doesn't create a new IndexFragment, it load the previously created fragment instead so every thing is fine in this case but when I go to the third or forth tab and then come back to first tab it creates an new instance of IndexFragment.
what's the possible reason for that and why it only happens for third,forth etc tab and only second tab works correct and as expected ????
here is my codes that switch the tabs and their corresponding fragments
public class TabsPagerAdapter extends FragmentPagerAdapter {
public TabsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int index) {
switch (index) {
case 0:
return new ForthPageFragment();
case 1:
return new ThirdPageFragment();
case 2:
return new SecondPageFragment();
case 3:
return new IndexFragment();
default :
break;
}
return null;
}
#Override
public int getCount() {
// get item count - equal to number of tabs
return 4;
}
}
and here is my main activity code :
public class MainActivity extends FragmentActivity implements
ActionBar.TabListener {
private ViewPager viewPager;
private TabsPagerAdapter mAdapter;
private ActionBar actionBar;
// Tab titles
private String[] tabs = { "صفحه چهارم","صفحه سوم","صفحه دوم","صفحه اصلی" };
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Initilization
viewPager = (ViewPager)findViewById(R.id.tabpager);
actionBar = getActionBar();
mAdapter = new TabsPagerAdapter(getSupportFragmentManager());
viewPager.setAdapter(mAdapter);
actionBar.setHomeButtonEnabled(false);
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// Adding Tabs
for (String tab_name : tabs) {
actionBar.addTab(actionBar.newTab().setText(tab_name)
.setTabListener(this));
}
viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageSelected(int position) {
// on changing the page
// make respected tab selected
actionBar.setSelectedNavigationItem(position);
}
#Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
#Override
public void onPageScrollStateChanged(int arg0) {
}
});
viewPager.setCurrentItem(3);
}
#Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
}
#Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
viewPager.setCurrentItem(tab.getPosition());
}
}

viewPager.setOffscreenPageLimit(3);

Android - Swiping without Tabs

NoteActivity Code:
public class NoteActivity extends FragmentActivity implements ActionBar.TabListener
{
private ViewPager viewPager;
private TabsPagerAdapter mAdapter;
private ActionBar actionBar;
// Tab titles
private String[] tabs = {"Note", "Note Info"};
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_note);
viewPager = (ViewPager) findViewById(R.id.pager);
actionBar = getActionBar();
mAdapter = new TabsPagerAdapter(getSupportFragmentManager());
viewPager.setAdapter(mAdapter);
actionBar.setHomeButtonEnabled(false);
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// Adding Tabs
for (String tab_name : tabs) {
actionBar.addTab(actionBar.newTab().setText(tab_name)
.setTabListener(this));
}
viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageSelected(int position) {
actionBar.setSelectedNavigationItem(position);
}
#Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
#Override
public void onPageScrollStateChanged(int arg0) {
}
});
}
#Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
// TODO Auto-generated method stub
viewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
// TODO Auto-generated method stub
}
#Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
// TODO Auto-generated method stub
}
}
TabsPageAdapter.Java
public class TabsPagerAdapter extends FragmentPagerAdapter
{
public TabsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int index) {
switch (index)
{
case 0:
return new NoteFragment();
case 1:
return new NoteInfoFragment();
}
return null;
}
#Override
public int getCount()
{
// get item count - equal to number of tabs
return 2;
}
}
So basically, I used an example of Tabs View and got the Tabs working and it looks like this:
What would I have to do to make it just swipeable without the Tabs showing. An example is like Snapchat. It definitely uses the Swipe view control but the tabs are hidden. Can someone please show me how to get this done?

Since you already have a ViewPager in your code, all you have to do is remove the code that creates the ActionBar tabs (under the comment // Adding tabs), as well as the code that synchronizes the tab selection with the current page (start with the ViewPager.OnPageChangeListener and the ActionBar.TabListener callbacks and see if anything breaks).

I don't want to refresh fragment on change

I have 3 fragments... with their 3 navigation tabs.
The problem is that if i'm on the first tab, and i click the third.. when I click another time the first, it reloads all the fragment. If I click the second tab (in the middle) and I click the first, it doesn't reload.
My objective is that I don't want to refresh my fragments never!
How can I do it?
My code is:
public class TabsPagerAdapter extends FragmentPagerAdapter {
public TabsPagerAdapter(FragmentManager fm) {
super(fm);
}
// Return Items
#Override
public Fragment getItem(int index) {
switch (index) {
case 0:
return new Retos();
case 1:
return new Amics();
case 2:
return new Ranking();
}
return null;
}
#Override
public int getCount() {
// get item count - equal to number of tabs
return 3;
}
}
And this :
public class Perfil extends ActionBarActivity implements ActionBar.TabListener{
private ViewPager viewPager;
private TabsPagerAdapter mAdapter;
private ActionBar actionBar;
private SearchView mSearchView;
private TextView mStatusView;
// Tab titles
private String[] tabs = { "TAB1", "TAB2", "TAB3" };
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.perfil);
// Initilization
viewPager = (ViewPager) findViewById(R.id.pager);
actionBar = getSupportActionBar();
mAdapter = new TabsPagerAdapter(getSupportFragmentManager());
viewPager.setAdapter(mAdapter);
actionBar.setHomeButtonEnabled(true);
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
/** Creating fragment1 Tab */
Tab tab = actionBar.newTab()
.setText("TAB1")
.setTabListener(this);
actionBar.addTab(tab);
/** Creating fragment2 Tab */
tab = actionBar.newTab()
.setText("TAB2")
.setTabListener(this);
//.setIcon(R.drawable.ic_action_group);
actionBar.addTab(tab);
/** Creating fragment3 Tab */
tab = actionBar.newTab()
.setText("TAB3")
.setTabListener(this);
actionBar.addTab(tab);
/**
* on swiping the viewpager make respective tab selected
* */
viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageSelected(int position) {
// on changing the page
// make respected tab selected
actionBar.setSelectedNavigationItem(position);
}
#Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
#Override
public void onPageScrollStateChanged(int arg0) {
}
});
}
#Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
}
#Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
// on tab selected
// show respected fragment view
viewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
}
}

viewPager.setOffscreenPageLimit(C_FRAGMENTS_TO_KEEP_IN_MEMORY);
C_FRAGMENTS_TO_KEEP_IN_MEMORY is the number of tabs at right and left of the current selected tab to keep in memory. So in your case should be 2.
Please be sure that you are NOT creating a new fragment instance each time you call the getItem method in you viewpager adapter.
Check the #Rarw answer in this page.

Try setting your ViewPager offScreenPageLimit to cover the number of fragments you are trying to load. OffScreenPageLimist keeps fragments alive in an idle state when they are not visible. I don't see that value set in your code and based on what you're describing, that fragments keep recycling, it sounds to me like you're using the default state of 1, which will only retain one of the fragments off screen and not both.
Some caveats, this approach only really works if you know in advance how many fragments you will need since if you're dynamically adding and removing fragments its hard to know how many if any to retain.
UPDATE
This is likely why you're pages are refreshing:
#Override
public Fragment getItem(int index) {
switch (index) {
case 0:
return new Retos();
case 1:
return new Amics();
case 2:
return new Ranking();
}
return null;
}
You keep returning a new fragment each time you switch id. What you should do something like this:
case 0:
if(mRetrosFragment == null)
mRetrosFragment = new Retros();
return mRetrosFragment;
This way you stop recreating the fragment every time the tab changes and instead retain that instance.

Call Activity which extends FragmentActivity using Fragment in android

I have Activity for tabLayout using ViewPager.
Code :
public class Home extends FragmentActivity implements ActionBar.TabListener {
private ViewPager viewPager;
private TabsPagerAdapter mAdapter;
private ActionBar actionBar;
private String[] tabs = { "Instant Opportunity", "Events", "Experts" };
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.home);
viewPager = (ViewPager) findViewById(R.id.pager);
actionBar = getActionBar();
mAdapter = new TabsPagerAdapter(getSupportFragmentManager());
viewPager.setAdapter(mAdapter);
actionBar.setHomeButtonEnabled(false);
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// Adding Tabs
for (String tab_name : tabs) {
actionBar.addTab(actionBar.newTab().setText(tab_name)
.setTabListener(this));
}
viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageSelected(int position) {
// on changing the page
// make respected tab selected
actionBar.setSelectedNavigationItem(position);
}
#Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
#Override
public void onPageScrollStateChanged(int arg0) {
}
});
}
#Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
}
#Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
viewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
}
}
And another activity for Slider, code is as below :
private void displayView(int position) {
// update the main content by replacing fragments
Fragment fragment = null;
switch (position) {
case 0:
fragment = new Home();
break;
case 1:
fragment = new Gallery();
break;
default:
break;
}
Now, here at case 0: I want to call that Home activity. But It is showing error. How to call this ?
When I take cursor on new Home(), It says can't convert from Home to Fragment.

You can use a ViewPager inside a Fragment. You have to use inner fragments with the nested fragments method, as you can read on the Documentation:
You can now embed fragments inside fragments. This is useful for a variety of situations in which you want to place dynamic and re-usable UI components into a UI component that is itself dynamic and re-usable. For example, if you use ViewPager to create fragments that swipe left and right and consume a majority of the screen space, you can now insert fragments into each fragment page.
You need to change Home as extends Fragment and use getChildFragmentManager() method for your adapter. There are some revelant posts on this kind of behaviour:
ViewPager inside ViewPager
How set ViewPager inside a Fragment
Display fragment viewpager within a fragment
How to add a Fragment inside a ViewPager using Nested Fragment (Android 4.2)
Hope this helps.

Android: Tab swipe from one fragment to other fragment

Hi in my project i am using a actionbar with three tabs which are fragments. now i have a button in fragment C, when i click the button i need to swipe back to fragment B, also i want to carry my data from fragment C to B this is secondary, can some one point me in right direction how can i achieve this .
Below is my MainActivty which has all the fragments
public class MainActivity extends FragmentActivity implements
ActionBar.TabListener {
private String[] tabs = { "fragA", "fragB", ""fragC", " };
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main)
// Initilization
viewPager = (ViewPager) findViewById(R.id.pager);
actionBar = getActionBar();
mAdapter = new TabsPagerAdapter(getSupportFragmentManager());
viewPager.setAdapter(mAdapter);
// Adding Tabs
for (String tab_name : tabs) {
actionBar.addTab(actionBar.newTab().setText(tab_name)
.setTabListener(this));
}
viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageSelected(int position) {
// on changing the page
// make respected tab selected
actionBar.setSelectedNavigationItem(position);
}
#Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
#Override
public void onPageScrollStateChanged(int arg0) {
}
});
}
#Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
}
#Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
// on tab selected
// show respected fragment view
viewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
}

I think this question is a duplicate, take a look here Android ActionBar Tabs - Swipe code is almost the same: a viewpager, an actionbar and you need transiction between fragments to be done with a swipe gesture.
Hope it helped you out ;)