How to refresh Android listview

Question

How to refresh an Android ListView after adding deleting dynamic data

User · Answer

Consider you have passed a list to your adapter  Use   list getAdapter   notifyDataSetChanged    to update your list

User · Answer

After deleting data from list view  you have to call refreshDrawableState    Here is the example   final DatabaseHelper db   new DatabaseHelper  ActivityName this    db open     db deleteContact arg3    mListView refreshDrawableState     db close      and deleteContact method in DatabaseHelper class will be somewhat looks like   public boolean deleteContact long rowId        return db delete TABLE NAME  BaseColumns  ID         rowId  null   gt  0

User · Answer

I was only able to get notifyDataSetChanged only by getting new adapter data  then resetting the adapter for the list view  then making the call like so        expandableAdapter   baseFragmentParent setupEXLVAdapter        baseFragmentParent setAdapter expandableAdapter       expandableAdapter notifyDataSetChanged

User · Answer

Please ignore all the invalidate    invalidateViews    requestLayout        answers to this question   The right thing to do  and luckily also marked as right answer  is to call notifyDataSetChanged   on your Adapter   Troubleshooting  If calling notifyDataSetChanged   doesn t work all the layout methods won t help either  Believe me the ListView was properly updated  If you fail to find the difference you need to check where the data in your adapter comes from   If this is just a collection you re keeping in memory check that you actually deleted from or added the item s  to the collection before calling the notifyDataSetChanged      If you re working with a database or service backend you ll have to call the method to retrieve the information again  or manipulate the in memory data  before calling the notifyDataSetChanged     The thing is this notifyDataSetChanged only works if the dataset has changed  So that is the place to look if you don t find changes coming through  Debug if needed    ArrayAdapter vs BaseAdapter  I did find that working with an adapter that lets you manage the collection  like a BaseAdapter works better  Some adapters like the ArrayAdapter already manage their own collection making it harder to get to the proper collection for updates  It s really just an needless extra layer of difficulty in most cases   UI Thread  It is true that this has to be called from the UI thread  Other answers have examples on how to achieve this  However this is only required if you re working on this information from outside the UI thread  That is from a service or a non UI thread  In simple cases you ll be updating your data from a button click or another activity fragment  So still within the UI thread  No need to always pop that runOnUiTrhead in   Quick Example Project  Can be found at https   github com hanscappelle so-2250770 git  Just clone and open the project in Android Studio  gradle   This project has a MainAcitivity building a ListView with all random data  This list can be refreshed using the action menu    The adapter implementation I created for this example ModelObject exposes the data collection  public class MyListAdapter extends BaseAdapter                   this is our own collection of data  can be anything we         want it to be as long as we get the abstract methods         implemented using this data and work on this data          see getter  you should be fine             private List lt ModelObject gt  mData                  our ctor for this adapter  we ll accept all the things         we need here                param mData             public MyListAdapter final Context context  final List lt ModelObject gt  mData            this mData   mData          this mContext   context             public List lt ModelObject gt  getData             return mData                implement all abstract methods here     Code from the MainActivity   public class MainActivity extends Activity        private MyListAdapter mAdapter        Override     protected void onCreate Bundle savedInstanceState            super onCreate savedInstanceState           setContentView R layout activity main            ListView list    ListView  findViewById R id list               create some dummy data here         List lt ModelObject gt  objects   getRandomData               and put it into an adapter for the list         mAdapter   new MyListAdapter this  objects           list setAdapter mAdapter               mAdapter is available in the helper methods below and the             data will be updated based on action menu interactions             you could also keep the reference to the android ListView             object instead and use the   link ListView getAdapter                method instead  However you would have to cast that adapter             to your own instance every time                       helper to show what happens when all data is new             private void reloadAllData               get new modified random data         List lt ModelObject gt  objects   getRandomData               update data in our adapter         mAdapter getData   clear            mAdapter getData   addAll objects              fire the event         mAdapter notifyDataSetChanged                          helper to show how only changing properties of data         elements also works             private void scrambleChecked            Random random   new Random               update data in our adapter  iterate all objects and             resetting the checked option         for  ModelObject mo   mAdapter getData                  mo setChecked random nextBoolean                          fire the event         mAdapter notifyDataSetChanged              More Information  Another nice post about the power of listViews is found here  http   www vogella com articles AndroidListView article html

User · Answer

I had an ArrayList which I wanted to display in a listview  ArrayList contained elements from mysql   I overrided onRefresh method and in that method I used tablelayout removeAllViews    and then repeated the process for getting data again from the database  But before that make sure to clear your ArrayList or whatever data structre or else new data will get appended to the old one

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on other option is onWindowFocusChanged method  but sure its sensitive and needs some extra coding for whom is interested   override fun onWindowFocusChanged hasFocus  Boolean            super onWindowFocusChanged hasFocus             some controls needed         programList   usersDBHelper readProgram model title            notesAdapter   DailyAdapter this  programList          notesAdapter notifyDataSetChanged           listview act daily adapter   notesAdapter

User · Answer

if you are not still satisfied with ListView Refreshment  you can look at this snippet this is for loading the listView from DB  Actually what you have to do is simply reload the ListView after you perform any CRUD Operation Its not a best way to code  but it  will refresh the ListView as you wish    It works for Me    if u find better solution please Share                     do your CRUD Operations                DBAdapter open    DBAdapter insert into SingleList       Bring that DB results and add it to list as its contents                                                 ls2 setAdapter new ArrayAdapter DynTABSample this      android R layout simple list item 1                         DBAdapter DB ListView                                                DBAdapter close

User · Answer

The easiest is to just make a new Adaper and drop the old one    myListView setAdapter new MyListAdapter

User · Answer

For me after changing information in sql database nothing could refresh list view  to be specific expandable list view  so if notifyDataSetChanged   doesn t help  you can try to clear your list first and add it again after that call notifyDataSetChanged    For example  private List lt List lt SomeNewArray gt  gt  arrayList  List lt SomeNewArray gt  array1  getArrayList       List lt SomeNewArray gt  array2  getArrayList       arrayList clear    arrayList add array1   arrayList add array2   notifyDataSetChanged      Hope it makes sense for you

User · Answer

If I talked about my scenario here  non of above answers will not worked because I had activity that show list of db values along with a delete button and when a delete button is pressed  I wanted to delete that item from the list   The cool thing was  I did not used recycler view but a simple list view and that list view initialized in the adapter class  So  calling the notifyDataSetChanged   will not do anything inside the adapter class and even in the activity class where adapter object is initialized because delete method was in the adapter class   So  the solution was to remove the object from the adapter in the adapter class getView method to only delete that specific object but if you want to delete all  call clear      To you to get some idea  what was my code look like   public class WordAdapter extends ArrayAdapter lt Word gt      Context context     public WordAdapter Activity context  ArrayList lt Word gt  words                         NonNull      Override     public View getView final int position  View convertView  ViewGroup group                         ImageButton deleteBt   listItemView findViewById R id word delete bt        deleteBt setOnClickListener new View OnClickListener               Override          public void onClick View v                 if  vocabDb deleteWord currentWord id                                            else                                                      remove getItem position        lt ---- here is the trick --- lt                 clear      if you want to clear everything                              Note  here remove   and getItem   methods are inherit from the Adapter class    remove   - to remove the specific item that is clicked getItem position  - is to get the item here  thats my Word object that I have added to the list  from the clicked position    This is how I set the adapter to the listview in the activity class       ArrayList lt Word gt  wordList   new ArrayList        WordAdapter adapter   new WordAdapter this  wordList        ListView list view    ListView  findViewById R id activity view words       list view setAdapter adapter

User · Answer

You need to use a single object of that list whoose data you are inflating on ListView  If reference is change then  notifyDataSetChanged   does t work  Whenever You are deleting elements from list view also delete them from the list you are using whether it is a ArrayList lt   or Something else then Call  notifyDataSetChanged   on object of Your adapter class   So here see how i managed it in my adapter see below  public class CountryCodeListAdapter extends BaseAdapter implements OnItemClickListener   private Context context  private ArrayList lt CountryDataObject gt  dObj  private ViewHolder holder  private Typeface itemFont  private int selectedPosition -1  private ArrayList lt CountryDataObject gt  completeList   public CountryCodeListAdapter Context context  ArrayList lt CountryDataObject gt  dObj        this context   context      this dObj dObj      completeList new  ArrayList lt CountryDataObject gt         completeList addAll dObj       itemFont Typeface createFromAsset context getAssets     CaviarDreams ttf        Override public int getCount         return dObj size        Override public Object getItem int position        return dObj get position       Override public long getItemId int position        return position     Override public View getView int position  View view  ViewGroup parent        if view  null           holder   new ViewHolder            LayoutInflater inflater    LayoutInflater  context getSystemService Context LAYOUT INFLATER SERVICE           view   inflater inflate R layout states inflator layout  null           holder textView     TextView view findViewById R id stateNameInflator            holder checkImg  ImageView view findViewById R id checkBoxState           view setTag holder        else          holder    ViewHolder  view getTag              holder textView setText dObj get position  getCountryName         holder textView setTypeface itemFont        if position  selectedPosition                  holder checkImg setImageResource R drawable check               else                 holder checkImg setImageResource R drawable uncheck              return view    private class ViewHolder      private TextView textView      private ImageView checkImg     public void getFilter String name        dObj clear        if  name equals           for  CountryDataObject item   completeList            if item getCountryName   toLowerCase   startsWith name toLowerCase   0                dObj add item                             else           dObj addAll completeList             selectedPosition -1      notifyDataSetChanged        notifyDataSetInvalidated         Override public void onItemClick AdapterView lt   gt  parent  View view  int position          long id        Registration reg  Registration context      selectedPosition position      reg setSelectedCountryCode     dObj get position  getCountryCode         notifyDataSetChanged

User · Answer

Also you can use this   myListView invalidateViews

User · Answer

If you want to maintain your scroll position when you refresh  and you can do this   if  mEventListView getAdapter      null        EventLogAdapter eventLogAdapter   new EventLogAdapter mContext  events       mEventListView setAdapter eventLogAdapter     else         EventLogAdapter mEventListView getAdapter    refill events      public void refill List lt EventLog gt  events        mEvents clear        mEvents addAll events       notifyDataSetChanged        For the detail information  please see Android ListView  Maintain your scroll position when you refresh

User · Answer

i got some problems with dynamic refresh of my listview      Call notifyDataSetChanged   on your Adapter       Some additional specifics on how when to call notifyDataSetChanged   can be viewed in this Google I O video    notifyDataSetChanged   did not work properly in my case  I called the notifyDataSetChanged from another class   Just in the case i edited the ListView in the running Activity  Thread   That video thanks to Christopher gave the final hint   In my second class i used  Runnable run   new Runnable         public void run             contactsActivity update              contactsActivity runOnUiThread run     to acces the update   from my Activity  This update includes  myAdapter notifyDataSetChanged      to tell the Adapter to refresh the view  Worked fine as far as I can say

User · Answer

If you are going by android guide lines and you are using the ContentProviders to get data from Database and you are displaying it in the ListView using the CursorLoader and CursorAdapters  then you all changes to the related data will automatically be reflected in the ListView   Your getContext   getContentResolver   notifyChange uri  null   on the cursor in the ContentProvider will be enough to reflect the changes  No need for the extra work around   But when you are not using these all then you need to tell the adapter when the dataset is changing  Also you need to re-populate   reload your dataset  say list  and then you need to call notifyDataSetChanged   on the adapter   notifyDataSetChanged  wont work if there is no the changes in the datset  Here is the comment above the method in docs-         Notifies the attached observers that the underlying data has been changed    and any View reflecting the data set should refresh itself

User · Answer

The solutions proposed by people in this post works or not mainly depending on the Android version of your device  For Example to use the AddAll method you have to put android minSdkVersion  10  in your android device   To solve this questions for all devices I have created my on own method in my adapter and use inside the add and remove method inherits from ArrayAdapter that update you data without problems   My Code  Using my own data class RaceResult  you use your own data model   ResultGpRowAdapter java  public class ResultGpRowAdapter extends ArrayAdapter lt RaceResult gt         Context context      int resource      List lt RaceResult gt  data null           public ResultGpRowAdapter Context context  int resource  List lt RaceResult gt  objects                      super context  resource  objects            this context   context          this resource   resource          this data   objects              Override     public View getView int position  View convertView  ViewGroup parent                                           my own method to populate data                    public void myAddAll List lt RaceResult gt  items             for  RaceResult item items               super add item                     ResultsGp java  public class ResultsGp extends Activity     Override protected void onCreate Bundle savedInstanceState                                         ListView list    ListView findViewById R id resultsGpList         ResultGpRowAdapter adapter   new ResultGpRowAdapter this   R layout activity result gp row  new ArrayList lt RaceResult gt        Empty data     list setAdapter adapter                                  LOAD a ArrayList lt RaceResult gt  with data     ArrayList lt RaceResult gt  data   new ArrayList lt RaceResult gt        data add new RaceResult            data add new RaceResult                        adapter myAddAll data     Your list will be udpdated

User · Answer

I was the same when  in a fragment  I wanted to populate a ListView  in a single TextView  with the mac address of BLE devices scanned over some time   What I did was this    public class Fragment01 extends android support v4 app Fragment implements           private ListView                listView      private ArrayAdapter lt String gt     arrayAdapter string         Override public void onActivityCreated Bundle savedInstanceState                this listView   ListView  super getActivity   findViewById R id fragment01 listView               this arrayAdapter string  new ArrayAdapter lt String gt  super getActivity    R layout dispositivo ble item  R id fragment01 item textView titulo       this listView setAdapter this arrayAdapter string        Override public void onLeScan BluetoothDevice device  int rssi  byte   scanRecord                super getActivity   runOnUiThread new RefreshListView device        private class RefreshListView implements Runnable       private BluetoothDevice bluetoothDevice       public RefreshListView BluetoothDevice bluetoothDevice                this bluetoothDevice  bluetoothDevice              Override     public void run                 Fragment01 this arrayAdapter string add new String bluetoothDevice toString              Fragment01 this arrayAdapter string notifyDataSetChanged              Then the ListView began to dynamically populate with the mac address of the devices found

User · Answer

Call runnable whenever you want   runOnUiThread run     OnCreate    you set your runnable thread   run   new Runnable         public void run               reload content         arraylist clear            arraylist addAll db readAll             adapter notifyDataSetChanged            listview invalidateViews            listview refreshDrawableState

User · Answer

If you want to update the UI listview from a service  then make the adapter static in your Main activity and do this     Override public void onDestroy         if  MainActivity isInFront    true            if  MainActivity adapter    null                MainActivity adapter notifyDataSetChanged                       MainActivity listView setAdapter MainActivity adapter

User · Answer

If you are using SimpleCursorAdapter try calling requery   on the Cursor object

User · Answer

I was not able to get notifyDataSetChanged   to work on updating my SimpleAdapter  so instead I tried first removing all views that were attached to the parent layout using removeAllViews    then adding the ListView  and that worked  allowing me to update the UI   LinearLayout results    LinearLayout findViewById R id results   ListView lv   new ListView this   ArrayList lt HashMap lt String String gt  gt  list   new ArrayList lt HashMap lt String String gt  gt     SimpleAdapter adapter   new SimpleAdapter  this  list  R layout directory row                   new String      name    dept     new int     R id name  R id dept       for              HashMap lt String  String gt  map   new HashMap lt String  String gt         map put  name   name       map put  dept   dept       list add map      lv setAdapter adapter   results removeAllViews         results addView lv

User · Answer

while using  SimpleCursorAdapter can call changeCursor newCursor  on the adapter

User · Answer

I think it depends on what you mean by refresh   Do you mean that the GUI display should be refreshed  or do you mean that the child views should be refreshed such that you can programatically call getChildAt int  and get the view corresponding to what is in the Adapter   If you want the GUI display refreshed  then call notifyDataSetChanged   on the adapter   The GUI will be refreshed when next redrawn   If you want to be able to call getChildAt int  and get a view that reflects what is what is in the adapter  then call to layoutChildren     This will cause the child view to be reconstructed from the adapter data

User · Answer

Call notifyDataSetChanged   on your Adapter object once you ve modified the data in that adapter    Some additional specifics on how when to call notifyDataSetChanged   can be viewed in this Google I O video

User · Answer

Just use myArrayList remove position   inside a listener     myListView setOnItemClickListener new AdapterView OnItemClickListener              Override public void onItemClick AdapterView lt   gt  parent  android view View view  int position  long id               myArrayList remove position              myArrayAdapter notifyDataSetChanged

[android] How to refresh Android listview?

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