Question

在我的Android应用程序中，它会显示带有选择框的月份列表。当您点击一个月时，它应该显示的值仅属于该月份。如果我选择1月份，则表示...但它显示其他月份的信息同样。

    // initialize values and settings
    private void initValues() {

        events = new ArrayList<>();
        eventPositions = new ArrayList<>();     
        progressDialog = new ProgressDialog(this);
        ServerManager serverManager = new ServerManager(this);
        progressDialog.show();
        serverManager.getEvents(authKey, loginType, 0);
        selectedMonth = -1;

        String[] months = {"Select month", "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"};
        List<String> monthList = new ArrayList<>(Arrays.asList(months));
          System.out.println(monthList);
        SelectionListAdapter selectionListAdapter = new SelectionListAdapter(this, monthList);
        Spinner monthSpinner = (Spinner)findViewById(R.id.calender_month_spinner);
        monthSpinner.setAdapter(selectionListAdapter);
        monthSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
        @Override
        public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {   
            calenderListAdepter.notifyDataSetChanged();

         }

         @Override
         public void onNothingSelected(AdapterView<?> parent) {
         }
        });
        dates = new ArrayList<>();
        hasEvent = new ArrayList<>();
        events = new ArrayList<>();
        calenderListAdepter = new CalenderListAdepter(this, events,hasEvent,dates);

//       calenderListAdepter = new CalenderListAdepter(this, dates, hasEvent);
        ListView gridView = (ListView) findViewById(R.id.calender_gridView);
        gridView.setAdapter(calenderListAdepter);    
    }

CalenderListAdepter

public class CalenderListAdepter extends BaseAdapter {

    private List<EventInfo> events;
    private Context context;
    private List<String> dates;
    private List<Boolean> hasEvent;       

    public CalenderListAdepter(Calender context, List<EventInfo> events, List<Boolean> hasEvent, List<String> dates) {

        this.context = context;
        this.events = events;
        this.dates=dates;
        this.hasEvent=hasEvent;

    }    

    @Override
    public int getCount() {
        return events.size();    
    }    

    @Override
    public Object getItem(int position) {
        return events.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        if (convertView == null) {
            LayoutInflater layoutInflater = (LayoutInflater)this.context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = layoutInflater.inflate(R.layout.calender_list_item, parent, false);
        }
        TextView messageText = (TextView)convertView.findViewById(R.id.message_textView);
        TextView dateText =(TextView)convertView.findViewById(R.id.date_textView);
        TextView titleText =(TextView)convertView.findViewById(R.id.Tile_textView);    

        if (position == 0)
            convertView.setBackgroundColor(Color.rgb(231, 231, 239));
        else {    

//        int month = Integer.parseInt(events.get(position).getMonth());
//        if (position==month){
            convertView.setBackgroundColor(Color.TRANSPARENT);                messageText.setText(events.get(position).getNoticeDescription());
            dateText.setText(events.get(position).getEventDate().toString());
            titleText.setText(events.get(position).getNoticeTitle().toString());    

        }   

        return convertView;
    }    

}

这是包含日期，hasevents的代码

    // set up the month view after selecting a month
    private void monthSelected() {
        eventPositions = new ArrayList<>();
        Calendar calendar = new GregorianCalendar();
        calendar.set(Calendar.DAY_OF_MONTH, 1);
        calendar.set(Calendar.MONTH, selectedMonth - 1);
        int currentYear = Calendar.getInstance().get(Calendar.YEAR);
        calendar.set(Calendar.YEAR, currentYear);
        int startDay = calendar.get(Calendar.DAY_OF_WEEK);
        int numberOfDays = calendar.getActualMaximum(Calendar.DATE);
        dates.clear();
        for (int i=1;i<startDay;i++) {
            dates.add("");
            hasEvent.add(false);
            eventPositions.add(-1);
        }
        for (int i=1;i<=numberOfDays;i++) {
            Integer eventPosition = -1;
            dates.add(String.valueOf(i));
            Boolean eventFlag = false;
            for (int j=0;j<events.size();j++) {
                Calendar eventCalender = Calendar.getInstance();
                eventCalender.setTime(events.get(j).getStampDate());
                int day = eventCalender.get(Calendar.DATE);
                int month = eventCalender.get(Calendar.MONTH);
                int year = eventCalender.get(Calendar.YEAR);
                if (day == i && month == (selectedMonth-1) && year == currentYear) {
                    eventFlag = true;
                    eventPosition = j;
                }
            }
            hasEvent.add(eventFlag);
            eventPositions.add(eventPosition);

        }
        int remaining = 42 - dates.size();
        for (int i=0;i<remaining;i++) {
            dates.add("");
            hasEvent.add(false);
            eventPositions.add(-1);
        }
        calenderListAdepter.notifyDataSetChanged();
    }    

    // shows details of an event
    public void showEventDetails(View view) {
        int tag = (int)view.getTag();
        int eventPosition = eventPositions.get(tag);
        AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(this);
        alertDialogBuilder.setTitle(events.get(eventPosition).getNoticeTitle());
        alertDialogBuilder.setMessage(events.get(eventPosition).getNoticeDescription());
        alertDialogBuilder.setPositiveButton("Ok", null);
        AlertDialog alert = alertDialogBuilder.create();
        alert.show();
    }    

    // shows an alert
    void showAlert(String alertMessage) {
        AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(this);
        alertDialogBuilder.setMessage(alertMessage);
        alertDialogBuilder.setPositiveButton("Ok", null);
        AlertDialog alert = alertDialogBuilder.create();
        alert.show();
    }

    // server response methods
    @Override
    public void requestFinished(String response, int requestTag) {
        if (progressDialog.isShowing())
            progressDialog.dismiss();
        boolean jsonError = false;
        try {
            JSONArray jsonArray = new JSONArray(response);
            for (int i=0;i<jsonArray.length();i++) {
                JSONObject jsonObject = jsonArray.getJSONObject(i);
                String title = jsonObject.optString("notice_title");
                String description = jsonObject.optString("notice");
                String month = jsonObject.optString("month");
                String timeStamp = jsonObject.optString("create_timestamp");
                long timeStampValue = Long.parseLong(timeStamp)*1000;
                Date date = new Date(timeStampValue);
                SimpleDateFormat formatter = new SimpleDateFormat("yyyy/MM/dd");
                String formattedDate = formatter.format(date);     

                String input = formattedDate;
                String[] out = input.split("/");
                int month1 = Integer.parseInt(out[1]);
//              System.out.println("Month = " + out[1]);   

                events.add(new EventInfo(title, description, timeStamp, formattedDate,month1,date,month));
            }
        }
        catch (JSONException e) {
            jsonError = true;
        }
        if (jsonError) {
            showAlert("An error occurred");
        }
    }    

    @Override
    public void requestFailed(String errorMessage, int requestTag) {    
    }

    @Override
    public void imageDownloaded(Bitmap image, int requestTag) {    
    }
}

Answer 1

您没有更新calenderListAdepter onItemSelected方法中的monthSpinner，这是用户进行选择时触发的方法。在调用notifyDataSetChanged()之前，您需要更新适配器中的数据才能生效。

Answer 2

就像@degs所说，你应该通过传递相应月份的新数据集来更新适配器。

您可以尝试两种方法：

<强>第一

您只能在用户点击的一个月内从服务器获取事件数据。在那里你应该创建一个查询来过滤＆＃34;月＆＃34;你后端的价值观。

monthSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
        // Here you can show progress dialog
        // and call a method to start fetching data from server
    }

    @Override
    public void onNothingSelected(AdapterView<?> parent) {
    }
});

然后使用requestFinished方法：

@Override
public void requestFinished(String response, int requestTag) {
    if (progressDialog.isShowing()) progressDialog.dismiss();
    boolean jsonError = false;
    try {
        JSONArray jsonArray = new JSONArray(response);
        for (int i = 0; i < jsonArray.length(); i++) {
            /* 
                Your current codes
            */
            events.add(new EventInfo(title, description, timeStamp, formattedDate, month1, date, month));
            calenderListAdepter.notifyDataSetChanged();
        }
    } catch (JSONException e) {
        jsonError = true;
    }
    if (jsonError) {
        showAlert("An error occurred");
    }
}

<强> SECOND

您从服务器获取所有数据并映射数据。

@Override
public void requestFinished(String response, int requestTag) {
    if (progressDialog.isShowing()) progressDialog.dismiss();

    // using SparseArray to map data with Integer key
    SparseArray<List<EventInfo>> allEventInfo = new SparseArray<>();
    boolean jsonError = false;
    try {
        // jsonArray should contain all events from all months
        JSONArray jsonArray = new JSONArray(response);
        for (int i = 0; i < jsonArray.length(); i++) {
            /* 
                Your current codes
            */

            // create a temp variable to store temporary list
            List<EventInfo> temp;

            // check whether allEventInfo already has a list with corresponding key. If yes, copy the list to temp otherwise initialize temp
            if (allEventInfo.get(month1) != null) {
                temp = allEventInfo.get(month1);
            } else temp = new ArrayList<>();

            // add temp with data from server
            temp.add(new EventInfo(title, description, timeStamp, formattedDate, month1, date, month));

            // put the list back to allEventInfo
            // at the end of for loop, allEventInfo should contains all events from all months
            allEventInfo.put(month1, temp);
        }
    } catch (JSONException e) {
        jsonError = true;
    }
    if (jsonError) {
        showAlert("An error occurred");
    }
}

然后，当用户点击monthSpinner中的项目时：

monthSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
        // get data for a month clicked only and add all data to events
        // position - 1 because you used index 0 for "Select month"
        events.addAll(allEventInfo.get(position - 1));
        // notify the adapter
        calenderListAdepter.notifyDataSetChanged();
    }

    @Override
    public void onNothingSelected(AdapterView<?> parent) {
    }
});

我想从android中的列表中只获取所选值

2 个答案: