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

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.

instead of

listItems.add("New Item");adapter.notifyDataSetChanged();

you can directly call

adapter.add("New Item");

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<String> adapter;private ArrayList<String> arrayList;@Overrideprotected 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<String>();    // 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<String>(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