android - fragment 中操作栏中的搜索 View

Question

我正在创建一个安卓应用程序。在应用程序中，我有一个登录页面。登录后会显示一个用户列表。用户列表 Activity 是 HomeActivity.java，它包含两个名为 UserListFragment.java 和 ChatFragment.java 的 fragment 火力基地。

UserListFragment.java 包含一个具有搜索菜单和注销菜单的操作栏。注销菜单工作正常，但搜索不工作。显示搜索图标，但当我搜索某些内容时，它不显示任何内容，即没有过滤器。我正在使用 firebase 来显示用户列表。

我不希望搜索 View 显示在 ChatFragment.java 中

我尝试了各种不同的解决方案。但没有一个对我有用。

这是代码。

UserListFragment.java

public class UsersListFragment extends Fragment {
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
Activity activity;
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
private static final String TAG = "UsersListFragment";
private OnFragmentInteractionListener mListener;
private ListView listView;
private List<UserData> users;
private CustomAdapter adapter;
SharedPreferences.Editor preferenceEditor;
Timer myTimer;
View view;
ActionBar actionBar;
private static final String PREFRENCES_NAME = "setPreferences";
private ProgressDialog progressBar;
String partnerKeyValue;

// TODO: Rename and change types and number of parameters
public static UsersListFragment newInstance(String param1, String param2) {
    UsersListFragment fragment = new UsersListFragment();
    Bundle args = new Bundle();
    args.putString(ARG_PARAM1, param1);
    args.putString(ARG_PARAM2, param2);
    fragment.setArguments(args);
    return fragment;
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
   Global.getInstance().unreadMessageUsers.clear();
    progressBar = new ProgressDialog(getActivity());
    progressBar.setCancelable(false);
    progressBar.setMessage("Loading...");
    progressBar.setProgressStyle(ProgressDialog.STYLE_SPINNER);
    progressBar.setProgress(0);
    }

@Override
public void onCreateOptionsMenu(Menu menu,MenuInflater inflater) {

    inflater.inflate(R.menu.menu_userlist,menu);
    MenuItem item = menu.findItem(R.id.menuSearch);

    SearchView searchView = (SearchView)item.getActionView();

    searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
        @Override
        public boolean onQueryTextSubmit(String query) {
            return false;
        }

        @Override
        public boolean onQueryTextChange(String newText) {
            Log.i(TAG,newText);
            adapter.getFilter().filter(newText);
            return true;
        }
    });

    super.onCreateOptionsMenu(menu,inflater);
}


private void logoutUser(){
    Intent I = new Intent(getActivity(), LoginActivity.class);
    startActivity(I);
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {

    switch (item.getItemId()) {
        case R.id.menuSearch :
            return true;

        case R.id.menuLogout :
            logoutUser();
            return true;

        default:
            return super.onOptionsItemSelected(item);
    }

}

menu_userlist.xml

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">

<item android:id="@+id/menuSearch"
    android:title="@string/search"
    android:icon="@drawable/ic_search"
    app:actionViewClass="android.widget.SearchView"
    app:showAsAction="always">
</item>

<item android:id="@+id/menuLogout"
    android:title="@string/logout"
    android:icon="@drawable/ic_logout"
    app:showAsAction="always">
</item>

CustomAdapter.java

@Override
public Filter getFilter() {
    Filter filter = new Filter() {

        @SuppressWarnings("unchecked")
        @Override
        protected void publishResults(CharSequence constraint,FilterResults results) {

            users = (List<UserData>) results.values; // has the filtered values
            notifyDataSetChanged();  // notifies the data with new filtered values
        }

        @Override
        protected FilterResults performFiltering(CharSequence constraint) {
            FilterResults results = new Filter.FilterResults();       

            List<String> FilteredArrList = new ArrayList<String>();

                if (mOriginalValues != null) {

                if (constraint == null || constraint.length() == 0) {

                    // set the Original result to return
                    results.count = mOriginalValues.size();
                    results.values = mOriginalValues;
                } else {
                    constraint = constraint.toString().toLowerCase();
                    for (int i = 0; i < mOriginalValues.size(); i++) {
                        String data = mOriginalValues.get(i).toString();
                        if (data.toLowerCase().contains(constraint.toString())) {
                            FilteredArrList.add(data);
                        }
                    }
                    // set the Filtered result to return
                    results.count = FilteredArrList.size();
                    results.values = FilteredArrList;
                }
            }

            return results;
        }
    };
    return filter;
}
}

Answer 1

更改以下代码段 -

@SuppressWarnings("unchecked")
    @Override
    protected void publishResults(CharSequence constraint,FilterResults results) {
        clear();
        addAll((List<UserData>) results.values)
        users = (List<UserData>) results.values; // has the filtered values

        notifyDataSetChanged();  // notifies the data with new filtered values
    }

这主要可以解决问题。但是您的源代码中存在很多不一致之处。您正在扩展已经实现了 Filterable 接口(interface)的 ArrayAdpater。

另请查看为什么需要以下状态变量 -

private List<UserData> messages;
private List<UserData> users;
private List<UserData> mOriginalValues;

请注意，您正在扩展 ArrayAdapter 并在构造函数中传递初始数据集。此后数据集的任何更改，您都需要在父级 ArrayAdapter 上重置它。仅仅更改子类中的状态变量是无济于事的。