Android 将项目添加到仅包含特定项目的 Listview.setAdapter

Question

有没有可能使用仅包含特定项目的 setAdapter 在 ListView 中添加项目？例如，我想在 ListView 中添加一个仅包含日期“2015 年 2 月 15 日”的项目。

代码如下:

   final ListAdapter adapter = new SimpleAdapter(CalendarActivity.this, eventsList, R.layout.calendar_event_list, new String[]{TAG_PID,
                    TAG_EVENTTITLE,TAG_EVENTSTART,TAG_EVENTEND},
                    new int[]{R.id.pid, R.id.eventname, R.id.eventstart, R.id.eventend});
            ListView myList = (ListView) findViewById(android.R.id.list);

            SimpleDateFormat formatdate = new SimpleDateFormat("MMM. dd, yyyy");
            String selecdate = formatdate.format(date);

            if (eventDates.contains(selecdate)) {
                    myList.setAdapter(adapter); //these line I want only to add items in listview which contains the value of 'selectdate'
            }
            else {
                myList.setAdapter(null);

            }

Answer 1

SimpleAdapter 用于静态数据。由于您想要动态过滤数据，因此您应该实现自定义适配器来执行此操作。但是，一个廉价的解决方案是在设置适配器之前过滤数据。像这样:

ListView myList = (ListView) findViewById(android.R.id.list);
SimpleDateFormat formatdate = new SimpleDateFormat("MMM. dd, yyyy");
String selecdate = formatdate.format(date);
// Filter selected events
List<Map<String, Object>> filteredEventsList = new ArrayList<Map<String, Object>>();
for (Map<STring, Object> row : eventsList) {
    if (row should be shown) {
        filteredEventsList.add(row);
    }
}

final ListAdapter adapter = new SimpleAdapter(CalendarActivity.this, filteredEventsList, R.layout.calendar_event_list, new String[]{TAG_PID,
                TAG_EVENTTITLE,TAG_EVENTSTART,TAG_EVENTEND},
                new int[]{R.id.pid, R.id.eventname, R.id.eventstart, R.id.eventend});
myList.setAdapter(adapter);