notifydatasetchanged

来源： https://stackoverflow.com/questions/47009273/recyclerview-notifydatasetchanged-is-not-working

来源： https://stackoverflow.com/questions/47009273/recyclerview-notifydatasetchanged-is-not-working

问题 There is a problem with notifyDataSetChanged. I have a list which retrieves data from sqlite database. The problem is that I know that I have to call notifyDataSetChanged everytime I use add method of list class. I can't understand why my list shows data after addAll() calling without the notifyDataSetChange(). I also tried using add() but result is the same. I need answer because I want to understand very well how notifyDataSetChange() works. Fragment code: public static List<Wherehouse>

问题 There is a problem with notifyDataSetChanged. I have a list which retrieves data from sqlite database. The problem is that I know that I have to call notifyDataSetChanged everytime I use add method of list class. I can't understand why my list shows data after addAll() calling without the notifyDataSetChange(). I also tried using add() but result is the same. I need answer because I want to understand very well how notifyDataSetChange() works. Fragment code: public static List<Wherehouse>

问题 Following this question: How to recreate all fragments in ViewPager: I have those classes: public class ViewPagerAdapter extends FragmentPagerAdapter { private List<Fragment> fragments; /** * @param fm * @param fragments */ public ViewPagerAdapter(FragmentManager fm, List<Fragment> fragments) { super(fm); this.fragments = fragments; } /* (non-Javadoc) * @see android.support.v4.app.FragmentPagerAdapter#getItem(int) */ @Override public Fragment getItem(int position) { return this.fragments.get

问题 I'm having some trouble with updating my ListView. So I used notifyDataSetChanged(); but it says that it can't be resolved. Heres the part of the code that is not working: public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main_activity2); background2= (RelativeLayout) findViewById(R.id.background); final ListView theListView = (ListView) findViewById(R.id.listView); Intent calledActivity=getIntent(); final List pe

问题 I'm having some trouble with updating my ListView. So I used notifyDataSetChanged(); but it says that it can't be resolved. Heres the part of the code that is not working: public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main_activity2); background2= (RelativeLayout) findViewById(R.id.background); final ListView theListView = (ListView) findViewById(R.id.listView); Intent calledActivity=getIntent(); final List pe

问题 I have an ArrayAdapter linked to a ListView. mListView.setAdapter(mArrayAdapter); Whenever I reset the ArrayList data to the ArrayAdapter: mArrayAdapter.clear(); mArrayAdapter.addAll(mArrayList); mArrayAdapter.notifyDataSetChanged() the ListView gets correctly updated however, if just after the above three lines, I call my custom method mListView.hasScrollbar() to detect whether the listview has a scrollbar or not, I get a null lastVisibleItem : public boolean hasScrollbar() { View

问题 If I call notifyDataSetChanged() on the custom adapter associated to my ListView, all the views should refresh themself ( getView() will be called). Now I have a BroadcastReceiver that is listening to an event. When the event fires, the ListView must be refreshed. How can I achieve this? Thanks! 回答1: If you refresh listview from receiver you'll have code like this: BroadcastReceiver br; public final static String BROADCAST_ACTION = "BROADCAST_ACTION"; br = new BroadcastReceiver() { public

问题 If I call notifyDataSetChanged() on the custom adapter associated to my ListView, all the views should refresh themself ( getView() will be called). Now I have a BroadcastReceiver that is listening to an event. When the event fires, the ListView must be refreshed. How can I achieve this? Thanks! 回答1: If you refresh listview from receiver you'll have code like this: BroadcastReceiver br; public final static String BROADCAST_ACTION = "BROADCAST_ACTION"; br = new BroadcastReceiver() { public