删除listView中的内容后，下一个创建的内容将取而代之而不是位于第一位

Question

因此，为了在listView中显示项目：我在一个片段和一个下载器，一个解析器和一个CustomAdapter中有一个listView。下载程序与php通信并下载数据，数据正在编码并在解析器中解码，因此customAdapter可以将这些内容放入listView中。我用Collections.reverse（玩家）排序我的列表;一切正常，我可以观看，我可以用另一个PHP和另一个类删除东西。如果我现在在MySQL中添加一些内容（因为我还使用了另一个片段，另一个类和另一个php），它将删除内容的位置而不是放在顶部。即使在MySQL中也需要它，所以我能做些什么才能将新内容放在顶端？ 我不知道问题是MySQL，添加过程，删除过程还是排序过程。

listView所在的片段：

public class BiologyFragment extends Fragment implements SwipeRefreshLayout.OnRefreshListener {

    String url = "http://tomeapp.esy.es/connectbiology.php";
    private SwipeRefreshLayout ll;
    private ListView lv;
    private boolean isRefreshing;
    private Handler refreshhandler = new Handler();
    FloatingActionButton addfab;
    FloatingActionButton help;
    FragmentManager manager;
    public BiologyFragment() {
        // Required empty public constructor
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {


        ll = (SwipeRefreshLayout)inflater.inflate(R.layout.fragment_subject, container, false);
        ll.setOnRefreshListener(this);
        lv = (ListView) ll.findViewById(R.id.lv);
        manager = getActivity().getSupportFragmentManager();
        new Downloader(getContext(), url, lv, manager).execute();

        SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(getContext());
        SharedPreferences.Editor editor = preferences.edit();
        editor.putString("last", "biology"); //TODO CHANGE ! IN EVERY SUBJECT DIFFERENT
        editor.apply();
        lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                //THE ONCLICK LISTENER IS INTEGRATED IN PARSER!!!
            }
        });

        addfab = (FloatingActionButton) ll.findViewById(R.id.add);
        addfab.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(getContext());
                SharedPreferences.Editor editor = preferences.edit();
                editor.putString("subjects", "biology"); //TODO CHANGE ! IN EVERY SUBJECT DIFFERENT
                editor.apply();
                AddFragment addFragment = new AddFragment();
                FragmentManager manager = getActivity().getSupportFragmentManager();
                manager.beginTransaction().replace(R.id.relative_layout_content_main, addFragment).commit();
            }
        });

        lv.setOnScrollListener(new AbsListView.OnScrollListener() {
            @Override
            public void onScrollStateChanged(AbsListView view, int scrollState) {
            }

            @Override
            public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
                boolean enable = false;
                if (lv != null && lv.getChildCount() > 0) {
                    // check if the first item of the list is visible
                    boolean firstItemVisible = lv.getFirstVisiblePosition() == 0;
                    // check if the top of the first item is visible
                    boolean topOfFirstItemVisible = lv.getChildAt(0).getTop() == 0;
                    // enabling or disabling the refresh layout
                    enable = firstItemVisible && topOfFirstItemVisible;
                }
                ll.setEnabled(enable);
            }

        });

        return ll;
    }

    @Override
    public void onRefresh() {
        new Downloader(getContext(), url, lv, manager).execute();
        refreshhandler.post(refreshing);
    }

    Runnable refreshing = new Runnable() {
        @Override
        public void run() {
            if(isRefreshing){
                // re run the verification after 1 second
            }else{
                // stop the animation after the data is fully loaded
                ll.setRefreshing(false);
            }
        }
    };


}

解析器：

public class Parser extends AsyncTask<Void,Integer,Integer> {

Context c;
ListView lv;
String data;
String result;

public static int id;
public static int idcounter;
public static String[] url = new String[100]; //TODO MAKE THE SIZE OF ARRAY EQUAL TO ID's AVAILABLE

List<String> authors = new ArrayList<>();
List<String> dates = new ArrayList<>();
List<String> titles = new ArrayList<>();
List<String> contents = new ArrayList<>();
ArrayList<SubjectsItem> players = new ArrayList<>(); //ÄNDERN
ProgressDialog pd;
FragmentManager manager2;

public Parser(Context c, String data, ListView lv, FragmentManager manager) {
    this.c = c;
    this.data = data;
    this.lv = lv;
    manager2 = manager;
}
@Override
protected void onPreExecute() {
    super.onPreExecute();
    pd = new ProgressDialog(c);
    pd.setTitle("Parser");
    pd.setMessage("Aktualisieren.. Bitte warten!");
    pd.show();

}

@Override
protected Integer doInBackground(Void... params) {

    return this.parse();
}

@Override
protected void onPostExecute(Integer integer) {
    super.onPostExecute(integer);

    if(integer == 1) {
        //ERSTELLE LV MIT ARRAY LIST
        ArrayAdapter<SubjectsItem> adapter = new SubjectAdapter(c, R.layout.fragment_subjects_listview, players);
        System.out.println(players);

        if(adapter != null && c != null) {

            lv.setAdapter(adapter);
            Collections.reverse(players); //TURNS AROUND THE LIST (PLAYERS)!
            System.out.println("PLAYERLIST : " + players);
        }
        else System.out.println("Adapter nicht gesetzt.");

        lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                //Toast.makeText(c,"CLICKED "+ position, Toast.LENGTH_SHORT).show();
                SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(c);
                SharedPreferences.Editor editor = preferences.edit();
                //editor.putString("", );
                editor.apply();
                System.out.println(authors.get(position));
                System.out.println(titles.get(position));

                editor.putString("author", authors.get(position));
                editor.putString("date", dates.get(position));
                editor.putString("title", titles.get(position));
                editor.putString("content", contents.get(position));
                editor.apply();

                FragmentManager manager = manager2;
                ContentFragment cFragment = new ContentFragment();
                manager.beginTransaction().replace(R.id.relative_layout_content_main, cFragment).commit();


            }                           /*Mit getX kann man entweder NewsItem, ID oder gar Text anzeigen!*/
        });
    } else {
        Toast.makeText(c,"Etwas ist beim Parsen schiefgelaufen!", Toast.LENGTH_SHORT).show();
    }

    pd.dismiss();
}
//PARSING RECEIVED DATA
private int parse() {               //PROBLEM ! (FIXED)
    try {
        //ADD DATA TO JSON ARRAY
        System.out.println(data);

        //CREATE JO OBJECT TO HOLD ONE ITEM
        JSONObject object = new JSONObject(data);

        JSONArray ja = object.getJSONArray("result");


        players.clear(); //ÄNDERN

        //LOOP ARRAY
        for(int i = 0; i < ja.length(); i++) {
            JSONObject jo = ja.getJSONObject(i);

            //RETRIEVE NAME
            id = jo.getInt("id");
            String author = jo.getString("author");
            String content = jo.getString("content");
            String title = jo.getString("title");
            String date = jo.getString("date");

            authors.add(author);
            dates.add(date);
            titles.add(title);
            contents.add(content);


            //ADD IT TO ARRAYLIST
            SubjectsItem eintrag = new SubjectsItem(id, author, content, title, date);
            players.add(eintrag);
            System.out.println(url[idcounter]);
            System.out.println(author + " " + content + " " + title + " " + date + "___________");

        }
        Collections.reverse(authors);
        Collections.reverse(dates);
        Collections.reverse(titles);
        Collections.reverse(contents);
        return 1;

    } catch (JSONException e) {
        e.printStackTrace();
    }
        return 0;
    }

}

php下载数据：

$con = mysqli_connect(HOST,USER,PASS,DB);

$sql = "SELECT title, content, author, id, date FROM biology";

$res = mysqli_query($con,$sql);

$result = array();

while($row = mysqli_fetch_array($res)){
array_push($result,
array('title'=>$row[0],
'content'=>$row[1],
'author'=>$row[2],
'id'=>$row[3],
'date'=>$row[4]
));
}

echo json_encode(array("result"=>$result));

mysqli_close($con);

我有很多课程和phps，所以如果你想告诉我你想在哪里仔细看看我会很高兴，我会在这里发布代码。

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