android - 如何在android中从Listadapter获取项目？

Question

我有一个Listadapter，其中有4个不同的字符串，并将它们存储到我的 ListView 中。现在我想从这些字符串之一获取所有项目并将其解析为“日期”，那么如何才能从列表适配器填充我的日历日期？

下面的代码:

  // Get User records from SQLite DB
    ArrayList<HashMap<String, String>> eventsList = controller.getAllevents();
    // If users exists in SQLite DB
    if (eventsList.size() != 0) {
        // Set the User Array list in ListView
        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);
        myList.setAdapter(adapter);

        String eventstart = adapter.toString(); //I got null exception here..

        Date edate = ParseDate(eventstart);

        if (caldroidFragment != null) {

            caldroidFragment.setBackgroundResourceForDate(R.color.Green, edate);
            caldroidFragment.refreshView();
        }
    }

Answer 1

如果您想从适配器中获取项目，您可以使用

adapter.getItem(position);

这将返回指定位置的项目。在您的情况下，该方法将返回 HashMap<String, String>在指定位置:

示例:

/* adapter.getCount() returns the count of how many items 
   (HashMaps, in your case) that is represented in this adapter. */
for(int i = 0; i < adapter.getCount(); i++){
     HashMap<String, String> myHashMap = adapter.getItem(i);
    //"myKey" is the key that you provided, when mapping your key-values
    String myVal = myHashMap.get("myKey");
    Date edate = ParseDate(myVal);
    /* Handle your Date object here. I'm just printing it to the console
       in this example. */        
    System.out.println("Item at position " + i + " " + edate.toString());
}