Java.lang.IllegalStateException:应用程序PagerAdapter更改了适配器的内容，而没有调用PagerAdapter#notifyDataSetChanged android [英] Java.lang.IllegalStateException: The application PagerAdapter changed the adapter's contents without calling PagerAdapter#notifyDataSetChanged android

问题描述

我试图使用静态类将值传递给视图，而不是使用意图，因为我必须传递大量数据.有时我会收到此错误，却找不到主要的原因

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 the main reason

错误:-

java.lang.IllegalStateException: The application's PagerAdapter changed the adapter's contents without calling PagerAdapter#notifyDataSetChanged! Expected adapter item count: 101, found: 200

我的寻呼机类

public class MemeDetailActivity extends AppCompatActivity implements OnDialogClickListner<Void> {
    private ViewPager mPager;
    private List<Datum> mList;
    private ScreenSlidePagerAdapter pagerAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_meme_detail);
        mList = DataResult.getInstance().getData();
        DataResult.getInstance().resetData();
        if (mList != null)
            startPager(selected_position);
        else
            Toast.makeText(this, "Error loading data", Toast.LENGTH_SHORT).show();
        // ATTENTION: This was auto-generated to implement the App Indexing API.
        // See https://g.co/AppIndexing/AndroidStudio for more information.
        client = new GoogleApiClient.Builder(this).addApi(AppIndex.API).build();
    }

    private void startPager(int position) {
        pagerAdapter = new ScreenSlidePagerAdapter(getSupportFragmentManager());
        mPager.setAdapter(pagerAdapter);
        pagerAdapter.notifyDataSetChanged();
        mPager.setOffscreenPageLimit(0);
        mPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

            }

            @Override
            public void onPageSelected(int position) {
                new Interactors(MemeDetailActivity.this).updateView(Util.getAccessToken(), mList.get(position).getId(), new OnFinishListner<ViewsRM>() {
                    @Override
                    public void onFinished(ViewsRM result) {

                    }

                    @Override
                    public void onFailed(String msg) {
                    }
                });
            }

            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });
        mPager.setCurrentItem(position);
    }

    public class ScreenSlidePagerAdapter extends FragmentStatePagerAdapter {
        SparseArray<Fragment> registeredFragments = new SparseArray<Fragment>();

        public ScreenSlidePagerAdapter(FragmentManager fm) {
            super(fm);
        }


        //todo entry point 3 : showing the image in the viewpager
        @Override
        public Fragment getItem(int position) {
            Fragment fragment = new fragment_mypager_new();
            Bundle bundle = new Bundle();
            if (frmMyMemes)
                bundle.putParcelable("MY_DATA", myList);
            bundle.putSerializable("DATA", mList.get(position));
            fragment.setArguments(bundle);
            return fragment;
        }

        @Override
        public int getItemPosition(Object object) {
            return POSITION_NONE;
        }

        @Override
        public int getCount() {
            return mList.size();
        }

        @Override
        public Object instantiateItem(ViewGroup container, int position) {
            Fragment fragment = (Fragment) super.instantiateItem(container, position);
            registeredFragments.put(position, fragment);
            return fragment;
        }

        @Override
        public void destroyItem(ViewGroup container, int position, Object object) {
            registeredFragments.remove(position);
            super.destroyItem(container, position, object);
        }

        public Fragment getRegisteredFragment(int position) {
            return registeredFragments.get(position);
        }
    }

}

我的静态课程

public class DataResult<T> {

    private static DataResult instance;
    private List<T> data = null;

    protected DataResult() {

    }

    public static synchronized DataResult getInstance() {
        if (instance == null) {
            instance = new DataResult();
        }
        return instance;
    }

    public List<T> getData() {
        return data;
    }

    public void setData(List<T> data) {
        this.data = data;
    }

    public void resetData() {
        data = null;
    }
}

我如何称呼活动

    Intent intent = new Intent(getActivity(), MemeDetailActivity.class);
    DataResult.getInstance().setData(mListA);

推荐答案

有时会发生此错误.

这是我的建议:

在您的DataResult-> getData()

返回数据的副本.

DataResult是单例，并保存数据.当您的视图获取数据时，该视图将获取DataResult所持有的数据引用.然后setData()将更改data引用.这是IllegalStateException.

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.

希望它会起作用:)

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