Updating the list view when the adapter data changes

Question

When the data associated with array adapter is changed  invalidating the listview is sufficient to show the updated values  Following piece of code is not working  did i misunderstood something here    public class ZeroItemListActivity extends Activity       private ArrayList lt String gt  listItems new ArrayList lt String gt         private ListView mMyListView          Called when the activity is first created          Override     public void onCreate Bundle savedInstanceState            super onCreate savedInstanceState           setContentView R layout main           mMyListView  ListView  findViewById R id MyListView           mMyListView setAdapter new ArrayAdapter lt String gt  this  android R layout simple list item 1 listItems              public void addItem View v           listItems add  list Item            mMyListView invalidate              Layout used     lt  xml version  1 0  encoding  utf-8   gt   lt LinearLayout xmlns android  http   schemas android com apk res android      android orientation  vertical  android layout width  fill parent      android layout height  fill parent  gt       lt TextView android layout width  fill parent          android layout height  wrap content  android text   string hello    gt       lt ListView android layout width  wrap content          android layout height  wrap content  android id    id MyListView  gt  lt  ListView gt       lt Button android layout width  wrap content          android layout height  wrap content  android id    id AddItemsButton          android text  Add Items  android onClick  addItem  gt  lt  Button gt   lt  LinearLayout gt

User · Answer

invalidate    calls the list view to invalidate itself  ie  background color   invalidateViews    calls all of its children to be invalidated  allowing you to update the children views  I assume its some type of efficiency thing preventing all of the items to constantly have to be redraw if not necessary

User · Answer

Change this line   mMyListView setAdapter new ArrayAdapter lt String gt  this                              android R layout simple list item 1                              listItems      to   ArrayAdapter lt String gt  adapter   new ArrayAdapter lt String gt  this                                     android R layout simple list item 1                                      listItems  mMyListView setAdapter adapter     and after updating the value of a list item  call   adapter notifyDataSetChanged

User · Answer

I found a solution that is more efficient than currently accepted answer  because current answer forces all list elements to be refreshed  My solution will refresh only one element  that was touched  by calling adapters getView and recycling current view which adds even more efficiency   mListView setOnItemClickListener new AdapterView OnItemClickListener          Override     public void onItemClick AdapterView lt   gt  parent  View view  int position  long id             Edit object data that is represented in Viewat at list s  position        view   mAdapter getView position  view  parent

User · Answer

substitute   mMyListView invalidate      for     BaseAdapter  mMyListView getAdapter    notifyDataSetChanged       If that doesnt work  refer to this thread  Android List view refresh

[android] Updating the list view when the adapter data changes

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