Java.lang.illegalstateexception: The Application Pageradapter Changed The Adapter's Contents Without Calling Pageradapter#notifydatasetchanged Android

I am trying to use a static class to pass value to a view instead of using intent as I have to pass a large amount of data. Sometimes I get this error and couldn't find out what is

Solution 1:

look at your code:

@Overridepublic int getItemPosition(Objectobject) {
            returnPOSITION_NONE;
        }

this code is use to refresh view when view change. it is also called notifyDataSetChanged()

its optional ovverride method so you can remove it.

Take a look at this answer: ViewPager PagerAdapter not updating the View

or else you can Change the FragmentStatePagerAdapter to FragmentPagerAdapter

Solution 2:

Sometimes this error occurs.

Here is my suggestion:

In your DataResult->getData()

return a copy of the data.

DataResult is a singleton and holds the data. When your view gets the data, the view gets the data reference witch the DataResult is holding. Then setData() would change the data reference. Here comes the IllegalStateException.

Hope it would work :)

Solution 3:

I think your DataResult class is not necessary.

According to your comment you are getting the error while you are updating the data set. I think you are getting data from some REST API or another web service. Then assign the data you gets from the API to a temporary Array List and update that temporary array list while you are getting new data. Don't touch the mListA variable until you finish receiving data. After complete getting data from the API assign the temporary array list you used to mListA directly in one line.

mListA = tmpList;

Then again call

mList = mListA;
pagerAdapter.notifyDataSetChanged();

This should solve your error.

Solution 4:

try using the following way:

mList=newArrayList<Datum>();
        mList.addAll(DataResult.getInstance().getData());
        DataResult.getInstance().resetData();

Solution 5:

It may because you first setAdapter() and notifyDataSetChanged in method initUI();

Then, you instantiate the List<?> data in method initData(), the two methods in different lifetime of fragment.

It's the problem about fragment's lifecycle