我有一个ListView片段，可以选择保存特定的表值。您可以单击按钮切换表以仅显示已保存的值。当切换激活而不是保存时，您可以选择删除值。我注意到，虽然只要应用程序打开，删除将永久删除值，如果我关闭应用程序并重新打开它，该值将重新出现。此外，如果我删除该应用程序并重新安装此相同的值重新出现。我不确定这个值是如何被添加的以及为什么它拒绝去。调试显示我在SharedPreferences中保存了正确的值，但这不会保留。
编辑：经过一些测试后，似乎保存在特定SharedPreferences中的第一个项目将永久保存。它无法删除，保存的所有其他值都不会保留。
Fragment：
package layout;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.preference.PreferenceManager;
import android.support.design.widget.FloatingActionButton;
import android.support.v4.widget.SwipeRefreshLayout;
import android.content.Context;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentTransaction;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.SearchView;
import android.widget.TextView;
import android.os.StrictMode;
import com.tble.brgo.HTMLPull;
import com.tble.brgo.InfoArticle;
import com.tble.brgo.R;
import android.widget.AdapterView.OnItemClickListener;
import java.io.IOException;
import java.lang.reflect.Array;
import java.util.ArrayList;
import android.text.TextUtils;
import java.util.HashSet;
import java.util.Set;
/**
* A simple {@link Fragment} subclass.
* Use the {@link Websites#newInstance} factory method to
* create an instance of this fragment.
*/
public class Websites extends Fragment implements SearchView.OnQueryTextListener, displayInterface {
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private SearchView mSearchView;
private ListView mListView;
public Boolean toggle = false;
public ArrayList<InfoArticle> mData = new ArrayList<InfoArticle>();
public StandardCellAdapter mAdapter;
public ArrayList<InfoArticle> fDataSet = new ArrayList<InfoArticle>();
public Websites webTable;
public Websites() {
// Required empty public constructor
}
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* @return A new instance of fragment Websites.
*/
// TODO: Rename and change types and number of parameters
public static Websites newInstance() {
Websites fragment = new Websites();
Bundle args = new Bundle();
fragment.setArguments(args);
return fragment;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
toggle = false;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_websites, container, false);
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
.permitAll().build();
StrictMode.setThreadPolicy(policy);
ArrayList<InfoArticle> data = new ArrayList<InfoArticle>();
webTable = this;
try {
data = getData();
} catch (IOException e) {
e.printStackTrace();
}
mListView = (ListView) view.findViewById(R.id.WebsiteTable);
final StandardCellAdapter adapter = new StandardCellAdapter(getActivity(), data, 1,this);
fDataSet = data;
mData = data;
mListView.setAdapter(adapter);
mAdapter = adapter;
mSearchView = (SearchView) view.findViewById(R.id.searchView);
mListView.setTextFilterEnabled(true);
FloatingActionButton myFab = (FloatingActionButton) view.findViewById(R.id.dataToggle);
myFab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
toggleView();
}
});
setupSearchView();
final SwipeRefreshLayout swipeLayout = (SwipeRefreshLayout) view.findViewById(R.id.webRefresh);
swipeLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
@Override
public void onRefresh() {
try {
mData = getData();
mAdapter = new StandardCellAdapter(getContext(), mData, 1,webTable);
mListView.setAdapter(mAdapter);
} catch (IOException e) {
e.printStackTrace();
}
swipeLayout.setRefreshing(false);
}
});
return view;
}
private void setupSearchView() {
mSearchView.setOnQueryTextListener(this);
mSearchView.setIconifiedByDefault(true);
}
private ArrayList<InfoArticle> getData() throws IOException {
SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(getContext());
int school = sharedPref.getInt("School", 14273);
HTMLPull Connection = new HTMLPull();
Connection.getStaff(school);
Connection.Results.remove(0);
return Connection.Results;
}
@Override
public boolean onQueryTextChange(String newText) {
if (TextUtils.isEmpty(newText)) {
mListView.clearTextFilter();
} else {
mListView.setFilterText(newText);
}
return true;
}
public ArrayList<InfoArticle> toData(ArrayList<String> t, ArrayList<String> d) {
ArrayList<InfoArticle> temp = new ArrayList<InfoArticle>();
if (t.size() == 0) {
temp.add(new InfoArticle("Slide to Save Teachers", "google.com"));
} else {
for (int i = 0; i < t.size(); i++) {
temp.add(new InfoArticle(t.get(i), d.get(i)));
}
}
return temp;
}
@Override
public boolean onQueryTextSubmit(String query) {
return false;
}
private void toggleView(){
if (!toggle) {
SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(getContext());
HashSet<String> defv = new HashSet<String>();
ArrayList<String> teachers = new ArrayList<String>(sharedPref.getStringSet("teachPref", defv));
ArrayList<String> links = new ArrayList<String>(sharedPref.getStringSet("linkPref", defv));
mAdapter = new StandardCellAdapter(getContext(), toData(teachers, links),2,this);
mListView.setAdapter(mAdapter);
toggle = true;
} else {
mAdapter = new StandardCellAdapter(getContext(), mData, 1,this);
mListView.setAdapter(mAdapter);
toggle = false;
}
}
/**public void displayWebpage(int position){
if (toggle == true) {
WebsiteDisplay fullView = WebsiteDisplay.newInstance(mAdapter.getItem(position).description);
FragmentTransaction transfer = getActivity().getSupportFragmentManager().beginTransaction();
transfer.replace(R.id.fragmentcontainer, fullView).addToBackStack("tag").commit();
} else {
if (!mSearchView.isIconified()) {
for (InfoArticle a : fDataSet) {
if (a.title.equals(((InfoArticle) mListView.getAdapter().getItem(position)).title)) {
WebsiteDisplay fullView = WebsiteDisplay.newInstance(a.description);
FragmentTransaction transfer = getActivity().getSupportFragmentManager().beginTransaction();
transfer.replace(R.id.fragmentcontainer, fullView).addToBackStack("tag").commit();
}
}
} else {
WebsiteDisplay fullView = WebsiteDisplay.newInstance(fDataSet.get(position).description);
FragmentTransaction transfer = getActivity().getSupportFragmentManager().beginTransaction();
transfer.replace(R.id.fragmentcontainer, fullView).addToBackStack("tag").commit();
}
}
}*/
public void displayWebpage(String Link){
WebsiteDisplay fullView = WebsiteDisplay.newInstance(Link);
FragmentTransaction transfer = getActivity().getSupportFragmentManager().beginTransaction();
transfer.replace(R.id.fragmentcontainer, fullView).addToBackStack("tag").commit();
}
}
CellAdapter：
package layout;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.SharedPreferences;
import android.media.Image;
import android.nfc.Tag;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.widget.RecyclerView;
import android.widget.ArrayAdapter;
import android.content.Context;
import android.view.View;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Set;
import android.preference.PreferenceManager;
import android.widget.ImageView;
import android.widget.TextView;
import android.view.LayoutInflater;
import android.view.ViewGroup;
import com.chauthai.swipereveallayout.SwipeRevealLayout;
import com.tble.brgo.InfoArticle;
import com.tble.brgo.R;
import android.graphics.Typeface;
import android.widget.Filterable;
import android.widget.Filter;
import org.w3c.dom.Text;
/**
* Created by Praveen on 8/21/16.
*/
public class StandardCellAdapter extends ArrayAdapter<InfoArticle> implements Filterable {
public ArrayList<InfoArticle> orig;
public ArrayList<InfoArticle> Teachers;
public SwipeRevealLayout swipeV;
public TextView deleteButton;
public TextView saveButton;
public int tableType;
public displayInterface activity;
public Context ct;
public StandardCellAdapter(Context context, ArrayList<InfoArticle> titles, int tableType, displayInterface inter) {
super(context, 0, titles);
this.Teachers = titles;
this.tableType = tableType;
saveButton = new TextView(context);
deleteButton = new TextView(context);
activity = inter;
ct = context;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// Get the data item for this position
String title = getItem(position).title;
String desc = getItem(position).description;
Holder TagHolder = null;
TextView Ctitle;
// Check if an existing view is being reused, otherwise inflate the view
if (convertView == null) {
if (tableType == 0) {
convertView = LayoutInflater.from(getContext()).inflate(R.layout.nclayout, parent, false);
Ctitle = (TextView) convertView.findViewById(R.id.cellTitle);
}
else if(tableType == 1){
convertView = LayoutInflater.from(getContext()).inflate(R.layout.sclayout, parent, false);
Ctitle = (TextView) convertView.findViewById(R.id.cellTitle);
TagHolder = new Holder();
swipeV = (SwipeRevealLayout)convertView.findViewById(R.id.scSwipe);
saveButton = (TextView)convertView.findViewById(R.id.saveButton);
TagHolder.Save = saveButton;
TagHolder.Cell = Ctitle;
convertView.setTag(TagHolder);
}
else{
convertView = LayoutInflater.from(getContext()).inflate(R.layout.tclayout, parent, false);
Ctitle = (TextView) convertView.findViewById(R.id.cellTitle);
TagHolder = new Holder();
swipeV = (SwipeRevealLayout)convertView.findViewById(R.id.tcSwipe);
deleteButton = (TextView) convertView.findViewById(R.id.deleteButton);
TagHolder.Delete = deleteButton;
TagHolder.Cell = Ctitle;
convertView.setTag(TagHolder);
}
}
else {
TagHolder = (Holder) convertView.getTag();
Ctitle = (TextView) convertView.findViewById(R.id.cellTitle);
}
if(tableType == 1) {
TagHolder.Save.setTag(position);
TagHolder.Save.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
saveTeacher((int)v.getTag());
}
});
TagHolder.Cell.setTag(position);
TagHolder.Cell.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
activity.displayWebpage(getItem((int)v.getTag()).description);
}
});
}
else if(tableType == 2) {
TagHolder.Delete.setTag(position);
deleteButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
deleteTeacher((int)v.getTag());
if(Teachers.size() == 0)
Teachers.add(new InfoArticle("Slide to Save Teachers", "google.com"));
notifyDataSetChanged();
}
});
TagHolder.Cell.setTag(position);
TagHolder.Cell.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
activity.displayWebpage(getItem((int)v.getTag()).description);
}
});
}
Typeface customFont = Typeface.SERIF;
Ctitle.setTypeface(customFont);
Ctitle.setText(title);
return convertView;
}
public Filter getFilter() {
return new Filter() {
@Override
protected FilterResults performFiltering(CharSequence constraint) {
final FilterResults oReturn = new FilterResults();
final ArrayList<InfoArticle> results = new ArrayList<InfoArticle>();
if (orig == null)
orig = Teachers;
if (constraint != null) {
if (orig != null && orig.size() > 0) {
for (final InfoArticle g : orig) {
if (g.title.toLowerCase()
.contains(constraint.toString().toLowerCase())) {
results.add(g);
}
}
}
oReturn.values = results;
}
return oReturn;
}
@SuppressWarnings("unchecked")
@Override
protected void publishResults(CharSequence constraint,
FilterResults results) {
Teachers = (ArrayList<InfoArticle>)results.values;
notifyDataSetChanged();
}
};
}
@Override
public void notifyDataSetChanged() {
super.notifyDataSetChanged();
}
public ArrayList<InfoArticle> toIA(ArrayList<String> data){
ArrayList<InfoArticle> converted = new ArrayList<InfoArticle>();
for(String a: data)
{
converted.add(new InfoArticle(a,""));
}
return converted;
}
@Override
public int getCount() {
return Teachers.size();
}
@Override
public InfoArticle getItem(int position) {
return Teachers.get(position);
}
public void saveTeacher(int position){
SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(getContext());
SharedPreferences.Editor editor = sharedPref.edit();
Set<String> teach = sharedPref.getStringSet("teachPref", new HashSet<String>());
teach.add(Teachers.get(position).title);
Set<String> link = sharedPref.getStringSet("linkPref", new HashSet<String>());
link.add(Teachers.get(position).description);
editor.putStringSet("teachPref", teach);
editor.putStringSet("linkPref", link);
editor.apply();
new AlertDialog.Builder(getContext())
.setTitle("Teacher Saved")
.setPositiveButton("Ok", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
// continue with delete
}
}).setIcon(android.R.drawable.ic_dialog_alert)
.show();
swipeV.close(true);
}
private void deleteTeacher(int position){
SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(getContext());
SharedPreferences.Editor editor = sharedPref.edit();
Set<String> teach = sharedPref.getStringSet("teachPref", new HashSet<String>());
Set<String> link = sharedPref.getStringSet("linkPref", new HashSet<String>());
teach.remove(Teachers.get(position).title);
link.remove(Teachers.get(position).description);
editor.putStringSet("teachPref", teach);
editor.putStringSet("linkPref", link);
editor.apply();
HashSet<String> defv = new HashSet<String>();
Teachers.remove(position);
new AlertDialog.Builder(getContext())
.setTitle("Teacher Deleted")
.setPositiveButton("Ok", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
// continue with delete
}
}).setIcon(android.R.drawable.ic_dialog_alert)
.show();
swipeV.close(false);
}
class Holder{
TextView Delete;
TextView Save;
TextView Cell;
}
}