notifyDataSetChanged() method is used to update the adapter.
Here I am posting a working answer steps by step.
First of main.xml file :
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:id="@+id/input">
<EditText
android:id="@+id/editText_input"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:ems="10" >
<requestFocus />
</EditText>
<Button
android:id="@+id/button_add"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="0"
android:text="Add" />
</LinearLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_above="@+id/input"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:orientation="vertical" >
<ListView
android:id="@+id/listView_items"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
</ListView>
</LinearLayout>
</RelativeLayout>
Here MainActivity.java :
import java.util.ArrayList;
import android.app.Activity;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
public class MainActivity extends Activity {
private EditText etInput;
private Button btnAdd;
private ListView lvItem;
private ArrayList<String> itemArrey;
private ArrayAdapter<String> itemAdapter;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.dyanamic_list);
setUpView();
}
private void setUpView() {
etInput = (EditText)this.findViewById(R.id.editText_input);
btnAdd = (Button)this.findViewById(R.id.button_add);
lvItem = (ListView)this.findViewById(R.id.listView_items);
itemArrey = new ArrayList<String>();
itemArrey.clear();
itemAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,itemArrey);
lvItem.setAdapter(itemAdapter);
btnAdd.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
addItemList();
}
});
etInput.setOnKeyListener(new View.OnKeyListener() {
public boolean onKey(View v, int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_ENTER) {
addItemList();
}
return true;
}
});
}
protected void addItemList() {
if (isInputValid(etInput)) {
itemArrey.add(0,etInput.getText().toString());
etInput.setText("");
itemAdapter.notifyDataSetChanged();
}
}
protected boolean isInputValid(EditText etInput2) {
if (etInput2.getText().toString().trim().length()<1) {
etInput2.setError("Please Enter Item");
return false;
} else {
return true;
}
}
}