【发布时间】：2018-01-11 13:36:14
【问题描述】：
有ViewPager 3 页 (FragmentPagerAdapter)
RealmRecyclerView 在第一页。
当Realm 为空时，表示“No items”消息和“Add”按钮。没关系。
所以，我已将我的第一个对象添加到 Realm。
EmptyView 仍然在这里，但我预计会看到 RealmRecyclerView (RRV)。
当我在 tab1 和 tab2 之间切换时，没有任何变化。
但是如果我切换到tab3，然后回到我的tab1 - RRV 终于出现了。
它不依赖于页面的内容。
RRV 的外观仅受 tab3 的返回影响。
我不明白原因。
我重新检查了我的TabViewPager、TabAdapter 和Fragments。
一切正常。
没有什么多余的，我认为这可能会影响这一点。
第二个问题：
当我通过SearchView 的查询过滤我的RRV 时，小部件 EmptyView 出现延迟。
例如：如果有“12345”项，则 EmptyView 仅在查询为“1234567”而不是“123456”时出现..
Аt 第一个不匹配的RRV 仍然可见，尽管它是空的。
并且仅当两个或多个字符 RRV 的差异消失时。
去除多余的字符也不能给出正确的表示。
我认为这两种情况都有一个原因。 你能指出错误吗？
FirstFragment.java
public class FirstFragment extends Fragment {
Realm realm;
RecyclerView realmRecyclerView;
FirstAdapter adapter;
TextView emptyText;
Button buttonAdd;
public FirstFragment () {
}
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View fragmentView = inflater.inflate(R.layout.fragment_first, container, false);
realm = Realm.getDefaultInstance();
realmRecyclerView = fragmentView.findViewById(R.id.recyclerView_first);
RealmResults<Object> results = realm.where(Object.class).findAll();
emptyText = fragmentView.findViewById(R.id.tv_no_data);
buttonAdd = fragmentView.findViewById(R.id.button_add);
setUpRealmRecyclerView();
initButtonAdd();
if (!results.isEmpty()) {
realmRecyclerView.setVisibility(View.VISIBLE);
emptyText.setVisibility(View.GONE);
buttonAdd.setVisibility(View.GONE);
} else {
realmRecyclerView.setVisibility(View.GONE);
emptyText.setVisibility(View.VISIBLE);
buttonAdd.setVisibility(View.VISIBLE);
}
return fragmentView;
}
private void setUpRealmRecyclerView() {
adapter = new FirstAdapter(realm, realm.where(Object.class).findAll());
realmRecyclerView.setHasFixedSize(true);
realmRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
realmRecyclerView.setAdapter(adapter);
FirstTouchHelper callback = new FirstTouchHelper(realm);
ItemTouchHelper touchHelper = new ItemTouchHelper(callback);
touchHelper.attachToRecyclerView(realmRecyclerView);
}
@Override
public void onDestroyView() {
super.onDestroyView();
realmRecyclerView.setAdapter(null);
realm.close();
}
private void initButtonAdd() {
//create new object dialog
}
@Override
public void onCreateOptionsMenu(final Menu menu, final MenuInflater inflater) {
inflater.inflate(R.menu.actionbar_menu, menu);
SearchManager searchManager = (SearchManager) getActivity().getSystemService(Context.SEARCH_SERVICE);
final SearchView searchView = (SearchView) menu.findItem(R.id.action_search).getActionView();
SearchableInfo searchableInfo = searchManager.getSearchableInfo(getActivity().getComponentName());
searchView.setSearchableInfo(searchableInfo);
searchView.setIconifiedByDefault(true);
EditText editTextSearch = (EditText) searchView.findViewById(android.support.v7.appcompat.R.id.search_src_text);
editTextSearch.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
}
@Override
public void onTextChanged(CharSequence charSequence, int start, int before, int count) {
}
@Override
public void afterTextChanged(Editable editable) {
adapter.getFilter().filter(editable);
if (adapter.getItemCount()==0) {
realmRecyclerView.setVisibility(View.GONE);
buttonAdd.setVisibility(View.VISIBLE);
} else {
realmRecyclerView.setVisibility(View.VISIBLE);
buttonAdd.setVisibility(View.GONE);
}
}
});
super.onCreateOptionsMenu(menu, inflater);
}
}
RRV 适配器：
public class FirstAdapter
extends RealmRecyclerViewAdapter<Object, RecyclerView.ViewHolder>
implements Filterable{
Realm realm;
public FirstAdapter(Realm realm, OrderedRealmCollection<Object> data) {
super(data, true, true);
this.realm = realm;
setHasStableIds(true);
}
@Override
public long getItemId(int index) {
return getItem(index).getId();
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.rrv_item, parent, false);
ObjectClass holder = new ObjectClass(v);
return holder;
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
Object object = getData().get(position);
ObjectClass classHolder = (ObjectClass) holder;
classHolder.name.setText(object.getName());
}
public void filterResults(String text) {
text = text == null ? null : text.toLowerCase().trim();
RealmQuery<Object> query = realm.where(Object.class);
if (text == null || "".equals(text)) {
updateData(query
.findAll()
.sort("name"));
} else {
updateData(query
.contains("name", text, Case.INSENSITIVE)
.findAll()
.sort("name"));
}
}
public Filter getFilter() {
ObjectFilter filter = new ObjectFilter(this);
return filter;
}
private class ObjectFilter
extends Filter {
private final FirstAdapter adapter;
private ObjectFilter(FirstAdapter adapter) {
super();
this.adapter = adapter;
}
@Override
protected FilterResults performFiltering(CharSequence constraint) {
return new FilterResults();
}
@Override
protected void publishResults(CharSequence constraint, FilterResults results) {
adapter.filterResults(constraint.toString());
}
}
private class ObjectClass
extends RecyclerView.ViewHolder {
TextView name;
private ObjectClass(View itemView) {
super(itemView);
name = itemView.findViewById(R.id.name_text_view);
}
}
}
【问题讨论】：
标签： android android-recyclerview android-viewpager realm android-tablayout