【发布时间】：2017-05-23 17:06:22
【问题描述】：
我正在尝试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，但无法找出主要原因
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
我的寻呼机课程
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);
}
}
}
我的静态类
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);
【问题讨论】：
-
mListA中的数据在调用DataResult.getInstance().setData(mListA);之后是否曾经修改（添加到）？ -
David Wasser 的评论指出了正确的解决方案 - 您不应该使用静态字段在 Activity/Fragment 之间进行通信。像你应该做的那样使用意图、内容提供者等。然后，您可以稍后根据需要进行优化。如果您在静态类中有此列表，并且在适配器中设置它之后正在对其进行修改，则它准确地解释了您遇到的错误。否则，请按照此问题中的步骤操作：stackoverflow.com/questions/22943658/…
标签： java android android-intent static singleton