How do you dynamically add elements to a ListView on Android

Question

Can anyone explain or suggest a tutorial to dynamically create a ListView in android  Here are my requirements   I should be able to dynamically add new elements by pressing a button  Should be simple enough to understand  possibly without any performance improvements or convertView  for instance   I know there are quite a few questions on this topic  but I couldn t find any that answer my question

User · Answer

Create an XML layout first in your project's res/layout/main.xml folder:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >
    <Button
        android:id="@+id/addBtn"
        android:text="Add New Item"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:onClick="addItems"/>
    <ListView
        android:id="@android:id/list"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:drawSelectorOnTop="false"
    />
</LinearLayout>

This is a simple layout with a button on the top and a list view on the bottom. Note that the ListView has the id @android:id/list which defines the default ListView a ListActivity can use.

public class ListViewDemo extends ListActivity {
    //LIST OF ARRAY STRINGS WHICH WILL SERVE AS LIST ITEMS
    ArrayList<String> listItems=new ArrayList<String>();

    //DEFINING A STRING ADAPTER WHICH WILL HANDLE THE DATA OF THE LISTVIEW
    ArrayAdapter<String> adapter;

    //RECORDING HOW MANY TIMES THE BUTTON HAS BEEN CLICKED
    int clickCounter=0;

    @Override
    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);
        setContentView(R.layout.main);
        adapter=new ArrayAdapter<String>(this,
            android.R.layout.simple_list_item_1,
            listItems);
        setListAdapter(adapter);
    }

    //METHOD WHICH WILL HANDLE DYNAMIC INSERTION
    public void addItems(View v) {
        listItems.add("Clicked : "+clickCounter++);
        adapter.notifyDataSetChanged();
    }
}

android.R.layout.simple_list_item_1 is the default list item layout supplied by Android, and you can use this stock layout for non-complex things.

listItems is a List which holds the data shown in the ListView. All the insertion and removal should be done on listItems; the changes in listItems should be reflected in the view. That's handled by ArrayAdapter<String> adapter, which should be notified using:

adapter.notifyDataSetChanged();

An Adapter is instantiated with 3 parameters: the context, which could be your activity/listactivity; the layout of your individual list item; and lastly, the list, which is the actual data to be displayed in the list.

User · Answer

This is the simple answer how to add datas dynamically in listview android kotlin   class MainActivity   AppCompatActivity                         var listItems   arrayListOf lt String gt                val array   arrayOf  quot a quot   quot b quot   quot c quot   quot d quot   quot e quot               var listView  ListView    null                  private lateinit var adapter  listViewAdapter                      override fun onCreate savedInstanceState  Bundle                     super onCreate savedInstanceState                  setContentView R layout scrollview layout                           listItems add  quot a quot                   listItems add  quot b quot                   listItems add  quot c quot                   listItems add  quot d quot                   listItems add  quot e quot                              if you want to add array items to a list you can try this for each loop                 for items in array                      listItems add items                                     check the result in console                 Log e  quot TAG quot   quot listItems array   listItems quot                    adapter   ListViewAdapter               adapter updateList listItems              adapter notifyDataSetChanged                                        Here is the adapter class     class ListviewAdapter   BaseAdapter             private var itemsList   arrayListOf lt String gt             override fun getView position  Int  container  View   parent  ViewGroup    View               var view    container             val inflater   context getSystemService Context LAYOUT INFLATER SERVICE  as LayoutInflater             if  view    null                  view   inflater inflate R layout list pc summary  parent  false           return view                override fun getItem position  Int   Any    itemsList position           override fun getItemId position  Int   Long   position toLong            override fun getCount    Int   itemsList size          fun updateList listItems  ArrayList lt String gt              this itemsList   listItems         notifyDatSetChanged                                        Here I just explained two ways  we can do this many ways

User · Answer

instead of   listItems add  New Item    adapter notifyDataSetChanged      you can directly call   adapter add  New Item

User · Answer

First  you have to add a ListView  an EditText and a button into your activity main xml   Now  in your ActivityMain   private EditText editTxt  private Button btn  private ListView list  private ArrayAdapter lt String gt  adapter  private ArrayList lt String gt  arrayList    Override protected void onCreate Bundle savedInstanceState        super onCreate savedInstanceState       setContentView R layout activity main        editTxt    EditText  findViewById R id editText       btn    Button  findViewById R id button       list    ListView  findViewById R id listView       arrayList   new ArrayList lt String gt             Adapter  You need three parameters  the context  id of the layout  it will be where the data is shown          and the array that contains the data     adapter   new ArrayAdapter lt String gt  getApplicationContext    android R layout simple spinner item  arrayList           Here  you set the data in your ListView     list setAdapter adapter        btn setOnClickListener new View OnClickListener              Override         public void onClick View view                    this line adds the data of your EditText and puts in your array             arrayList add editTxt getText   toString                    next thing you have to do is check if your adapter has changed             adapter notifyDataSetChanged                          This works for me  I hope I helped you

User · Answer

Code for MainActivity java file   public class MainActivity extends Activity        ListView listview      Button Addbutton      EditText GetValue      String   ListElements   new String              Android            PHP               Override     protected void onCreate Bundle savedInstanceState            super onCreate savedInstanceState           setContentView R layout activity main            listview    ListView  findViewById R id listView1           Addbutton    Button  findViewById R id button1           GetValue    EditText  findViewById R id editText1            final List  lt  String  gt  ListElementsArrayList   new ArrayList  lt  String  gt               Arrays asList ListElements              final ArrayAdapter  lt  String  gt  adapter   new ArrayAdapter  lt  String  gt               MainActivity this  android R layout simple list item 1                  ListElementsArrayList            listview setAdapter adapter            Addbutton setOnClickListener new View OnClickListener                   Override             public void onClick View v                     ListElementsArrayList add GetValue getText   toString                     adapter notifyDataSetChanged                                        Code for activity main xml layout file    lt RelativeLayout    xmlns android  http   schemas android com apk res android    xmlns tools  http   schemas android com tools    android layout width  match parent    android layout height  match parent    android paddingBottom   dimen activity vertical margin    android paddingLeft   dimen activity horizontal margin    android paddingRight   dimen activity horizontal margin    android paddingTop   dimen activity vertical margin    tools context  com listviewaddelementsdynamically android examples      com MainActivity   gt      lt Button     android id    id button1      android layout width  fill parent      android layout height  wrap content      android layout below    id editText1      android layout centerHorizontal  true      android text  ADD Values to listview    gt      lt EditText     android id    id editText1      android layout width  wrap content      android layout height  wrap content      android layout alignParentTop  true      android layout centerHorizontal  true      android layout marginTop  26dp      android ems  10      android hint  Add elements listView    gt      lt ListView     android id    id listView1      android layout width  match parent      android layout height  wrap content      android layout below    id button1      android layout centerHorizontal  true   gt     lt  ListView gt    lt  RelativeLayout gt    ScreenShot

User · Answer

The short answer  when you create a ListView you pass it a reference to the data  Now  whenever this data will be altered  it will affect the list view and thus add the item to it  after you ll call adapter notifyDataSetChanged      If you re using a RecyclerView  update only the last element  if you ve added it at the end of the list of objs  to save memory with  mAdapter notifyItemInserted mItems size   - 1

User · Answer

If you want to have the ListView in an AppCompatActivity instead of ListActivity  you can do the following  Modifying  Shardul s answer    public class ListViewDemoActivity extends AppCompatActivity         LIST OF ARRAY STRINGS WHICH WILL SERVE AS LIST ITEMS     ArrayList lt String gt  listItems new ArrayList lt String gt            DEFINING A STRING ADAPTER WHICH WILL HANDLE THE DATA OF THE LISTVIEW     ArrayAdapter lt String gt  adapter         RECORDING HOW MANY TIMES THE BUTTON HAS BEEN CLICKED     int clickCounter 0      private ListView mListView        Override     public void onCreate Bundle icicle            super onCreate icicle           setContentView R layout activity list view demo            if  mListView    null                mListView    ListView  findViewById R id listDemo                      adapter new ArrayAdapter lt String gt  this                  android R layout simple list item 1                  listItems           setListAdapter adapter                METHOD WHICH WILL HANDLE DYNAMIC INSERTION     public void addItems View v            listItems add  Clicked     clickCounter             adapter notifyDataSetChanged               protected ListView getListView             if  mListView    null                mListView    ListView  findViewById R id listDemo                     return mListView             protected void setListAdapter ListAdapter adapter            getListView   setAdapter adapter              protected ListAdapter getListAdapter             ListAdapter adapter   getListView   getAdapter            if  adapter instanceof HeaderViewListAdapter                return   HeaderViewListAdapter adapter  getWrappedAdapter              else               return adapter                      And in you layout instead of using android id   android id list  you can use android id    id listDemo   So now you can have a ListView inside a normal AppCompatActivity

[android] How do you dynamically add elements to a ListView on Android?

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