Android：有活动的日历 [英] Android: Calendar with Events

问题描述

我在Android中有关于日历的问题。我想添加数据库上的事件。我基本上想要的是当我打开我的日历片段时，它将调用Web服务并从服务器中获取数据，其中包括日期和相应的事件，当我在日历中点击该日期时，显示指定日期的事件。我遇到的问题是：

I have some issue regarding calendar in android. I want to add events which is on database. What I basically want is when i open my calendar fragment it will call web service and fetch the data from the server which includes dates and their respective events when i click on that date in calendar it shows me the events on specified date. Issues which i faced are:

1. 它在此行上显示一些错误 date = sdf.parse（日期）; ，它说

java.lang.NullPointerException
   at java.text.SimpleDateFormat.parse(SimpleDateFormat.java:1009)
   at java.text.DateFormat.parse(DateFormat.java:553)
   at com.example.aksystems.practiceportal.Calendar.showJSON(Calendar.java:118)

成功运行前两天，问题是会生成点日历日两次。示例：我的服务器响应是

Two days before it runs successfully and the issue is it will generate point on calendar day twice. Example: my server response is

[{"d":"a","events":"2017\/04\/13 18:20:43"},{"d":"a","events":"2017\/04\/10 18:20:40"}]`

所以它会指出日期13一次和日期10这么多次为什么？

so it will point date 13 once and date 10 so many times why?

Calendar.java

Calendar.java

public class Calendar extends Fragment {

    CalendarView calendarView;

    private EditText editTextId;
    private Button buttonGet;
    private TextView textViewResult;
    String dates,events;
    private ProgressDialog loading;
    CompactCalendarView compactCalendarView;
    String id = "a";
    SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
    Date date = null;
    public Calendar() {}

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

        View view = inflater.inflate(R.layout.fragment_layout_calendar, container, false);

        compactCalendarView = (CompactCalendarView) view.findViewById(R.id.compactcalendar_view);

        editTextId = (EditText) view.findViewById(R.id.editTextId);
        buttonGet = (Button)view. findViewById(R.id.buttonGet);
        textViewResult = (TextView) view.findViewById(R.id.textViewResult);
        getData();

        return view;

    }
    private void getData() {


        loading = ProgressDialog.show(getActivity(),"Please wait...","Fetching...",false,false);

        String url = Config.DATA_URL+"?e="+id;

        StringRequest stringRequest = new StringRequest(url, new Response.Listener<String>()
        {
            @Override
            public void onResponse(String response) {
                loading.dismiss();
                showJSON(response);
            }
        },
                new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        Toast.makeText(getActivity(),error.getMessage().toString(),Toast.LENGTH_LONG).show();
                    }
                });

        RequestQueue requestQueue = Volley.newRequestQueue(getActivity());
        requestQueue.add(stringRequest);
    }

    private void showJSON(String response)
    {

        for (int i=0;i < response.length();i++)

        {
            try {

                JSONObject jsonObject = new JSONObject(response);
                JSONArray result = jsonObject.getJSONArray(Config.JSON_ARRAY);
                JSONObject collegeData = result.getJSONObject(i);
                dates = collegeData.getString(Config.KEY_DATES);
                events = collegeData.getString(Config.KEY_EVENTS);
                //vc = collegeData.getString(Config.KEY_VC);*/

            } catch (JSONException e) {
                e.printStackTrace();
            }
            // textViewResult.setText(""+dates);

            // String myDate = "2017/03/30 18:10:45";

            try
            {
                date = sdf.parse(dates);
            } catch (ParseException e) {
                e.printStackTrace();
            }
            // Convert Date into milliseconds
            assert date != null;
            long millis = date.getTime();

            Event ev1 = new Event(Color.RED, millis, events);
            compactCalendarView.addEvent(ev1);
           /* List<Event> events = compactCalendarView.getEvents(millis);
            Toast.makeText(getActivity(), "" + events, Toast.LENGTH_SHORT).show();*/
            compactCalendarView.setListener(new CompactCalendarView.CompactCalendarViewListener()
            {
                @Override
                public void onDayClick(Date dateClicked) {
                    List<Event> events = compactCalendarView.getEvents(dateClicked);

                    // Log.d(TAG, "Day was clicked: " + dateClicked + " with events " + events);
                    Toast.makeText(getActivity(), "" + events, Toast.LENGTH_SHORT).show();
                }

                @Override
                public void onMonthScroll(Date firstDayOfNewMonth)
                {
                    //  Log.d(TAG, "Month was scrolled to: " + firstDayOfNewMonth);
                   // Toast.makeText(getActivity(), "Month was scrolled to: " + firstDayOfNewMonth, Toast.LENGTH_SHORT).show();
                }
            });
        }
    }
}

推荐答案

1. 这是因为您传递的日期不是当前格式。看到你的PHP脚本。


2. 你的变量 response.length（）返回值超过两个，所以它将指向多个事件在最后一天。尝试使用 JSONArray.size（）来查找响应的长度。

1. This is because your passed date is not in current format. See your PHP script.
2. Your varibleresponse.length() returns value more than two so it will point to more than one events in last date. Try using JSONArray.size() to find the length of response.

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