我的ListView有问题。我正在创建新对象，并通过单击第一个片段中的按钮将其添加到数据库中。在第二个片段中，我从我的数据库中获得了包含对象的listview。一切正常，但第二个片段中的listView不刷新 - 我只在重新启动应用程序后看到新对象。所有解决方案如：notifyDataSetChanged都不起作用：/
这是我的第一个片段的适配器：
public class ConcertAdapter extendsRecyclerView.Adapter<ConcertAdapter.MyViewHolder> {
private static final String FRAGMENT_TAG = "fragmentTag";
private static final String TAG = ConcertAdapter.class.getSimpleName() ;
private LayoutInflater inflater;
private Context context;
private List<Concert> concertList = new ArrayList<>();
private DatabaseHelper mDatabaseHelper = null;
private int selectedRecordPosition = -1;
private MainActivity mActivity;
public ConcertAdapter(Context context, List<Concert> concerts, MainActivity mainActivity) {
this.inflater = LayoutInflater.from(context);
this.concertList = concerts;
this.context = context;
this.mActivity = mainActivity;
}
public void setListConcert(ArrayList<Concert> concertList) {
this.concertList = concertList;
notifyItemRangeChanged(0, concertList.size());
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = inflater.from(parent.getContext()).inflate(R.layout.concert_item, parent, false);
return new MyViewHolder(view);
}
@Override
public void onBindViewHolder(final MyViewHolder holder, final int position) {
final float screenWidthPx = holder.itemView.getResources().getDisplayMetrics().widthPixels;
Concert current = concertList.get(position);
Log.d("mLog", current.getUrl());
holder.mImage.setImageUrl(current.getUrl(), MySingleton.getInstance().getImageLoader());
holder.mImage.getLayoutParams().height = (int) (screenWidthPx * 0.50);
holder.mFav_btn.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
if(isChecked) {
final Concert favConcert = new Concert();
favConcert.setTitle(concertList.get(position).getTitle());
favConcert.setContent(concertList.get(position).getContent());
favConcert.setDate(concertList.get(position).getDate());
favConcert.setUrl(concertList.get(position).getUrl());
try {
final Dao<Concert, Integer> concertDao = getHelper().getConcertDao();
concertDao.create(favConcert);
}catch (SQLException e) {
e.printStackTrace();
}
}
}
});
SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Date concertDate = new Date();
try {
concertDate = format.parse(current.getDate());
} catch (ParseException e) {
e.printStackTrace();
}
DateTime dt = new DateTime();
DateTime currentDate = dt.withZone(DateTimeZone.forID("Europe/Warsaw"));
int days = Days.daysBetween(new DateTime(currentDate), new DateTime(concertDate)).getDays();
String s = String.valueOf(days);
holder.mDate_btn.setText(s + " dni");
if (s.equals("0")) {
holder.mDate_btn.setText("dziś :)");
}
}
@Override
public int getItemCount() {
return concertList.size();
}
public void setConcerts(List<Concert> concerts) {
concertList = new ArrayList<>(concerts);
}
public void showDisplay(int position) {
Bundle bundle = new Bundle();
bundle.putInt("position", position);
bundle.putString("content", concertList.get(position).getContent());
bundle.putString("date", concertList.get(position).getDate());
bundle.putString("url", concertList.get(position).getUrl());
bundle.putString("title", concertList.get(position).getTitle());
Fragment fragment = new DisplayConcertFragment();
fragment.setArguments(bundle);
mActivity.replaceFragment(fragment);
}
class MyViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
public NetworkImageView mImage;
public Button mDate_btn;
public TextView mBubble;
public ToggleButton mFav_btn;
public ImageView mBubbleImage;
private ConcertFragment mConcertFragment;
public MyViewHolder(View itemView) {
super(itemView);
mImage = (NetworkImageView) itemView.findViewById(R.id.concerts_niv);
mDate_btn = (Button) itemView.findViewById(R.id.date_btn);
mImage.setOnClickListener(this);
mFav_btn = (ToggleButton) itemView.findViewById(R.id.fav_btn);
}
@Override
public void onClick(View v) {
showDisplay(getAdapterPosition());
//ft.setCustomAnimations(android.R.animator.fade_in, android.R.animator.fade_out);
Toast.makeText(context, "TEST", Toast.LENGTH_LONG).show();
}
public Concert removeItem(int position) {
final Concert concert = concertList.remove(position);
notifyItemRemoved(position);
return concert;
}
}
private DatabaseHelper getHelper() {
if (mDatabaseHelper == null) {
mDatabaseHelper = OpenHelperManager.getHelper(context,DatabaseHelper.class);
}
return mDatabaseHelper;
}
这是我的第二个适配器：
public class FavAdapter extends ArrayAdapter {
private LayoutInflater mInflater;
private List mRecords;
private Dao<Concert, Integer> concertDao;
private Button mDateButton;
private NetworkImageView mImage;
public FavAdapter(Context context, int resource, List objects, Dao<Concert, Integer> concertDao) {
super(context, resource, objects);
this.mRecords = objects;
this.concertDao = concertDao;
mInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
if(convertView == null)
convertView = mInflater.inflate(R.layout.concert_item, parent, false);
if(mRecords.get(position).getClass().isInstance(new Concert())){
final Concert concert = (Concert) mRecords.get(position);
mImage =((NetworkImageView)convertView.findViewById(R.id.concerts_niv));
mImage.setImageUrl(concert.getUrl(), MySingleton.getInstance().getImageLoader());
final float screenWidthPx = mImage.getResources().getDisplayMetrics().widthPixels;
mImage.getLayoutParams().height = (int) (screenWidthPx * 0.50);
mDateButton = (Button) convertView.findViewById(R.id.date_btn);
Date concertDate = new Date();
SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
try {
concertDate = format.parse(concert.getDate());
} catch (ParseException e) {
e.printStackTrace();
}
DateTime dt = new DateTime();
DateTime currentDate = dt.withZone(DateTimeZone.forID("Europe/Warsaw"));
int days = Days.daysBetween(new DateTime(currentDate), new DateTime(concertDate)).getDays();
String s = String.valueOf(days);
mDateButton.setText(s + " dni");
if (s.equals("0")) {
mDateButton.setText("dziś :)");
}
// ((TextView)convertView.findViewById(R.id.teacher_tv)).setText(studentDetails.teacher.teacherName);
}
return convertView;
}
}
这是我使用ListView的第二个片段：
public class FavFragment extends Fragment {
private static final String TAG = FavFragment.class.getSimpleName() ;
private DatabaseHelper mDatabaseHelper = null;
private ListView mListView;
private int selectedRecordPosition = -1;
private Dao<Concert, Integer> concertDao;
private List<Concert> concertList;
private MainActivity mActivity;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_fav_layout, container, false);
mListView = (ListView)v.findViewById(R.id.concerts_lv);
mActivity = (MainActivity) getContext();
try {
concertDao = getHelper().getConcertDao();
concertList = concertDao.queryForAll();
FavAdapter adapter = new FavAdapter(getContext(), R.layout.concert_item, concertList, concertDao);
mListView.setAdapter(adapter);
adapter.notifyDataSetChanged();
mListView.invalidateViews();
mListView.refreshDrawableState();
} catch (SQLException e) {
e.printStackTrace();
}
Log.e(TAG, "onCreateView notify");
return v;
}
private DatabaseHelper getHelper() {
if (mDatabaseHelper == null) {
mDatabaseHelper = OpenHelperManager.getHelper(getContext(), DatabaseHelper.class);
}
return mDatabaseHelper;
}
@Override
public void onDestroy() {
super.onDestroy();
if (mDatabaseHelper != null) {
OpenHelperManager.releaseHelper();
mDatabaseHelper = null;
}
}
}
这是我的第一个片段
public class ConcertFragment extends Fragment implements MyBackPressed {
private static final String FRAGMENT_TAG = "fragmentTag";
private static final String TAG = ConcertFragment.class.getSimpleName() ;
public ProgressBar progress;
private ConcertLoader concertLoader;
private RecyclerView recyclerView;
private Context mContext;
private android.support.v4.app.FragmentManager mFragmentManager;
private MainActivity mActivity;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
JodaTimeAndroid.init(getContext());
View v = inflater.inflate(R.layout.fragment_concert_layout, container, false);
progress = (ProgressBar) v.findViewById(R.id.progressBar);
recyclerView = (RecyclerView) v.findViewById(R.id.concerts_rv);
concertLoader = new ConcertLoader(ConcertFragment.this);
mActivity = (MainActivity) getContext();
futureConcerts();
return v;
}
public void futureConcerts() {
concertLoader.execute();
getActivity().getWindow().getDecorView().getRootView().setClickable(false);
}
public void notifyAboutListCreation(List<Concert> res) {
ConcertAdapter adapter = new ConcertAdapter(getActivity().getApplicationContext(), res, mActivity);
recyclerView.setAdapter(adapter);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity().getApplicationContext()));
progress.setVisibility(View.GONE);
adapter.notifyDataSetChanged();
}
@Override
public void onBackPressed() {
getActivity().finish();
}
}
答案 0 :(得分：1)
前一段时间我遇到过类似的问题。您是否从非UI线程触发任何UI更新？也许来自听众内部？尝试使用以下代码来触发UI更新。
runOnUiThread(new Runnable(){
@Override
public void run(){
...
adapter.notifyDataSetChanged();
mListView.invalidateViews();
mListView.refreshDrawableState();
...
}
});
就我个人而言，我现在已经开始将一个有问题的代码块包装在一个通用的try-catch块中，该块捕获Exception并查看是否有任何异常我监督（使用带有标记过滤器的终端上的logcat）。
（无法发表评论，所以以这种方式回答）