TabPagerIndicator goes wrong with Navigation drawer

Question

The sample code demonstrating the issue is here:

https://github.com/Beeder/TestTabPager

(Better formatted Question, please see my github project TestTabPager README)

It is exported from Android Studio 0.8.6

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I am new to android programming, recently I use navigation drawerand viewpageindicator, but i got stuck here.

Select item0, show item0 fragment with three tabs correctly, select item1, when done, select item0 again, item0 fragment with three tabs showed but only three tabs showed, the corresponding inner fragment was gone! More strangely, when I slide among these three tabs, TAB0's and TAB2's inner fragments showed again, but TAB1's inner fragment never showed! WHY?

Here is the details: According to this tutorial(www.tutecentral.com/android-custom-navigation-drawer/), I create a navigation drawer activity like this:

raw.githubusercontent.com/Beeder/MyStorage/master/Image/TestTabPager/Screenshot_2014-10-06-17-25-59.png

(Sorry I don't have more than 10 reputation, you can paste the url to browser and see the image.)

In order to demonstrate, only two drawer items were added. when select item 0, here goes item0 fragment(which named NewsFragment in my project):

raw.githubusercontent.com/Beeder/MyStorage/master/Image/TestTabPager/Screenshot_2014-10-06-17-26-14.png

In NewsFragment, I use JakeWharton's Android-ViewPagerIndicator(github.com/JakeWharton/Android-ViewPagerIndicator), more specifically TabPageIndicator. There are three tabs, select one tab, corresponding TabFragment(x) showed.

When select drawer item1, show:

raw.githubusercontent.com/Beeder/MyStorage/master/Image/TestTabPager/Screenshot_2014-10-06-17-26-24.png

But, when I select drawer item0 again, everything was gone except the three tabs! That means the TabFragment(x)'s TextView isn't showed. WHY?

More Strangely, After I slide among these three tabs, TAB0's and TAB2's inner fragments(TextView) showed again, but TAB1's inner fragment never showed! WHY? Is that because TAB1 is in the middle?

I have tried many ways to work it out, In NewsFragment, i override onStop() and onViewStateRestored() to get the last selected tab, but tabPageIndicator.setCurrentItem(selectedItem);doesn't seem to really trigger Fragment getItem(int position) method, the selected tab's inner fragment isn't created again!

@Override
    public void onStop() {
        super.onStop();

        SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getActivity());
        SharedPreferences.Editor editor = sharedPreferences.edit();
        editor.putInt("NewsSelected",pager.getCurrentItem());
        editor.commit();

        Log.d("MyTag", "NEWS--onStop");
    }



@Override
    public void onViewStateRestored(Bundle savedInstanceState) {
        super.onViewStateRestored(savedInstanceState);

        SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getActivity());
        int selectedItem=sharedPreferences.getInt("NewsSelected",0);//Default value =0
        Toast.makeText(getActivity(), "Last time, you chose TAB"+selectedItem, Toast.LENGTH_SHORT).show();
        tabPageIndicator.setCurrentItem(selectedItem);//reselect the tab last selected. but the inner fragment isn't recreated, i got empty, why?
        //pager.setAdapter(tabPageIndicatorAdapter);
        //tabPageIndicator.setViewPager(pager);

        Log.d("MyTag", "NEWS--onViewStateRestored");
    }

I guess it has something to do with not saving InstanceState, but i don't know what else to do, I have struggled two days, I'd appreciate it if you could help me.

Thanks again.

Answer 1

after digging into it, I have figure it out.

FragmentPagerAdapter, it turns out, is the main issue. After replace FragmentPagerAdapter with FragmentStatePagerAdapter and track all active inner fragment down, I have solved my problem.

Many thanks to this answer.

If you can read Chinese, this blog may help you understand better.

For detail information, feel free to see my project's README!