How to make if back to previous fragment Tab ViewPagerIndicator not reload again?

Question

i have error with tab viewpagerindicator, if if back or swipe to previous fragment is always reload...

this my code fragment

package com.droidersuin.project.viewpagerindicator;


import com.droidersuin.project.app.ContentActivity;

import android.content.Context;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;

public class ViewAdapter extends FragmentPagerAdapter{

    private Context _context;
    String[] page_titles;

    public ViewAdapter(Context context, FragmentManager fm, String[] page_title){
        super(fm);
        _context = context;
        this.page_titles = page_title;
    }

    @Override
    public Fragment getItem(int position) {
        // TODO Auto-generated method stub

        Fragment f = new Fragment();

    switch(position){
    case 0:
        f = ContentActivity.newInstance(_context);
        break;

    case 1:
        f = ContentActivity.newInstance(_context);
        break;
    case 2:
        f = ContentActivity.newInstance(_context);
        break;

    }

    return f;
}

@Override
public int getCount() {
    // TODO Auto-generated method stub
    return page_titles.length;
}

    public CharSequence getPageTitle(int position) {
        return page_titles[position];
    }



}

if i swipe from fragment 0 to fragment index 1 and back swipe to index 0, is always reload content, i want to make if back swipe to previous fragment not reload again ? how it

thanks... sorry for my english ..

Answer 1

Try to set your viewPager's offScreenPageLimit like this:

 mPager.setOffscreenPageLimit(3); 

it will keep your three pages in memory, and after them it will start reloading.

Answer 2

I think you shold try to override getItemId Method like that:

@Override
public long getItemId(int position) {
    return position;
}

If you check FragmentPagerAdapter's source code you will find it did this in instantiateItem method

final long itemId = getItemId(position);
    // Do we already have this fragment?
    String name = makeFragmentName(container.getId(), itemId);
    Fragment fragment = mFragmentManager.findFragmentByTag(name);

FragmentPagerAdapter uses item id to identify if fragment has already been instantiated.

https://github.com/android/platform_frameworks_support/blob/master/v4/java/android/support/v4/app/FragmentPagerAdapter.java