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How to refresh Android listview?

How to refresh an Android ListView after adding/deleting dynamic data?

If other solutions don't work, try refreshDrawableState. Props to stackoverflow.com/questions/5186359/…
An example here tutorialkart.com/kotlin-android/… may help you.

K
Kaushik

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.


You should run it on the UI thread. Create an handler within the UI thread and then post Runable to it
Once again: notifyDataSetChanged() does not work at least not for use practices which are recomended (read not deprecated). If use listview, cursor adapter and content provider you might try something along the lines: gettLoaderManager().restartLoader(). See: stackoverflow.com/a/19657500/1087411 I would like to see at least some documentation on notifyDataSetChanged(). To much in android is left to black box testing.
If notifyDataSetChanged does not work, you are the one who is doing it wrong
notifyDataSetChanged does not always work. I'm not sure why this is in contention. Sometimes you have to call listView.setAdapter(adapter) to clear out the old views. See also: stackoverflow.com/a/16261588/153275
I was never able to get notifyDataSetChanged working. I could clearly see that the collection I feed to the adapter has changed (elements were removed) but notifyDataSetChanged has never done anything. Not sure if this method is just broken?
n
nbro

Also you can use this:

myListView.invalidateViews();

This is the correct answer if one only needs to REDRAW the view. For example, after a user login occurs that needs to expose more info or options within each view of the listView. That's what I needed to do, so gave an up-vote. If the underlying data changes, it's probably a better idea to use notifyDataSetChanged().
Actually invalidateViews() in the source code sets mDataChanged = true; so I'm not sure if this results in better performance compared to notifyDataSetChanged()
You saved my day, dude!
you can take a type of list which is "observable list" ,no need to notifydataset changed
actually this helped me. notifyDataChanged() didnt update the view.
J
JJD

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<ModelObject> mData;

    /**
     * our ctor for this adapter, we'll accept all the things 
     * we need here
     *
     * @param mData
     */
    public MyListAdapter(final Context context, final List<ModelObject> mData) {
        this.mData = mData;
        this.mContext = context;
    }

    public List<ModelObject> 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<ModelObject> 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<ModelObject> 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


you're wrong. notifyDataSetChanged() didn't worked for me, but invalidateViews() did it right.
I have the issue where the actual elements in the list do not change, e.g. same amount of elements. But the problem is that the way they are presented needs to change. That means my adapter's code to build the UI needs to run again and then correctly hide some element in the list rows. notifyDataSetChanged() does not work...
This answer really helped me out. I was keeping the array in memory for certain feature reasons. To fix it I now call adapter.clear(), and adapter.addAll(Array<T>) before calling notifyDataSetChanged()
@hcpl, how should I call notifyDataSetChanged if I'm in the adapter's OnClickListener for a CheckBox? invalidateViews is getting the job done right now. Why is invalidateViews the wrong method to call?
I was never able to get notifyDataSetChanged working. I could clearly see that the collection I feed to the adapter has changed (elements were removed) but notifyDataSetChanged has never done anything. Not sure if this method is just broken?
A
Amirhossein Mehrvarzi

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();
    }
};

Working also in my case, where I need to update a listview based on data coming from a TCP connection (from a "nonUI" thread). The only way to have the list redrawn was to clear and re-add all the elements of the ArrayList. Anyway, if you are already in the UI thread you don't need to call the code via the runOnUiThread() function.
Thanks! It works for me. For all people who want to run this from a fragment, you should use getActivity().runOnUiThread(new Runnable... to make sure the code is run on UI thread
I do not see the purpose of run = new Runnable() and just gave my function a public void refreshUIThread() method that models your run() method (which works, too).
w
whostolemyhat

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.


f
freehacker

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


This method is deprecated.
N
Nandagopal T

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();

C
ChrisF

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<RaceResult> {

    Context context;
    int resource;
    List<RaceResult> data=null;

        public ResultGpRowAdapter(Context context, int resource, List<RaceResult> 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<RaceResult> 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<RaceResult>()); //Empty data

   list.setAdapter(adapter);

   .... 
   ....
   ....
   //LOAD a ArrayList<RaceResult> with data

   ArrayList<RaceResult> data = new ArrayList<RaceResult>();
   data.add(new RaceResult(....));
   data.add(new RaceResult(....));
   .......

   adapter.myAddAll(data); //Your list will be udpdated!!!

A
Aivus

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<List<SomeNewArray>> arrayList;
List<SomeNewArray> array1= getArrayList(...);
List<SomeNewArray> array2= getArrayList(...);
arrayList.clear();
arrayList.add(array1);
arrayList.add(array2);
notifyDataSetChanged();

Hope it makes sense for you.


j
jww

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<EventLog> events) {
    mEvents.clear();
    mEvents.addAll(events);
    notifyDataSetChanged();
}

For the detail information, please see Android ListView: Maintain your scroll position when you refresh.


S
Steffo Dimfelt

Just use myArrayList.remove(position); inside a listener:

  myListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override public void onItemClick(AdapterView<?> parent, android.view.View view, int position, long id) {
           myArrayList.remove(position);
           myArrayAdapter.notifyDataSetChanged();
        }
    });

A
ADM

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<> 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<CountryDataObject> dObj;
private ViewHolder holder;
private Typeface itemFont;
private int selectedPosition=-1;
private ArrayList<CountryDataObject> completeList;

public CountryCodeListAdapter(Context context, ArrayList<CountryDataObject> dObj) {
    this.context = context;
    this.dObj=dObj;
    completeList=new  ArrayList<CountryDataObject>();
    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<?> parent, View view, int position,
        long id) {
    Registration reg=(Registration)context;
    selectedPosition=position;
    reg.setSelectedCountryCode("+"+dObj.get(position).getCountryCode());
    notifyDataSetChanged();
}
}

your explanation are underrated, but it's really give me understanding about arraylist reference. thank you
M
Mahdi-Malv

Consider you have passed a list to your adapter. Use:

list.getAdapter().notifyDataSetChanged()

to update your list.


A
Ant4res

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) > 0;

}

C
Chasden

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<HashMap<String,String>> list = new ArrayList<HashMap<String,String>>();
SimpleAdapter adapter = new SimpleAdapter( this, list, R.layout.directory_row, 
                new String[] { "name", "dept" }, new int[] { R.id.name, R.id.dept } );

for (...) { 
    HashMap<String, String> map = new HashMap<String, String>();
    map.put("name", name);
    map.put("dept", dept);
    list.add(map);
}

lv.setAdapter(adapter);
results.removeAllViews();     
results.addView(lv);

V
Vihaan Verma

while using SimpleCursorAdapter can call changeCursor(newCursor) on the adapter.


j
jsanmarb

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<String>    arrayAdapter_string;

...

@Override
public void onActivityCreated(Bundle savedInstanceState)
{
    ...
    this.listView= (ListView) super.getActivity().findViewById(R.id.fragment01_listView);
    ...
    this.arrayAdapter_string= new ArrayAdapter<String>(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.


d
dazed

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.


C
CodeSsscala

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..


Z
Ziem

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);
    }
}    

S
Sanjeet A

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.
 */

K
Kristy Welsh

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(); 

S
Samir

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
    }

B
Blasanka

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<Word> {
  Context context;

  public WordAdapter(Activity context, ArrayList<Word> 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)); // <---- here is the trick ---<
             //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<Word> wordList = new ArrayList();
    WordAdapter adapter = new WordAdapter(this, wordList);

    ListView list_view = (ListView) findViewById(R.id.activity_view_words);
    list_view.setAdapter(adapter);

u
user1712200

The easiest is to just make a new Adaper and drop the old one:

myListView.setAdapter(new MyListAdapter(...));

This consumes more memory.
the garbage will be collected