title: Add Items to ListView - Android
body: <p>This is my first experience with android. I'm trying to add items to my ListView.
  I use Tabs, and the only way to see that the item was added is to change tab and then come back to the first tab.</p>
  
  <p>I searched around, and I've always found</p>
  
  <pre><code>adapter.notifyDataSetChanged();
  </code></pre>
  
  <p>but doesn't work for me.</p>
  
  <p>I have created the project with, as I said, Fixed Tabs + Swipe.
  I simply want to have listviews which rows have an EditText, a Spinner and a Button.
  On the bottom of the Fragment used for the tab, I have an ImageButton. I want to click on it and have a new Row.</p>
  
  <p>my custom Adapter:</p>
  
  <pre><code>package com.andreapivetta.uconverter;
  
  import java.util.ArrayList;
  
  import android.content.Context;
  import android.view.LayoutInflater;
  import android.view.View;
  import android.view.ViewGroup;
  import android.widget.ArrayAdapter;
  
  public class CustomAdapter extends ArrayAdapter&lt;String&gt; {
  private final Context context;
  private final int resourceID;
  
      public CustomAdapter(Context context, int resource, ArrayList&lt;String&gt; bah) {
          super(context, resource, bah);
  
          this.context = context;
          this.resourceID = resource;
      }
  
      @Override
      public View getView(int position, View convertView, ViewGroup parent) {
          LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
          View rowView = inflater.inflate(resourceID, parent, false);
  
          return rowView;
      }
  }
  </code></pre>
  
  <p>fragment_main_dummy.xml</p>
  
  <pre><code>&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=".MainActivity$DummySectionFragment" &gt;
  
  &lt;ListView
      android:id="@+id/unitListView"
      android:layout_width="match_parent"
      android:layout_height="wrap_content" &gt;
  &lt;/ListView&gt;
  
  &lt;ImageButton
      android:id="@+id/moreImageButton"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
  
      android:layout_alignParentBottom="true"
      android:layout_alignParentRight="true"
  
      android:contentDescription="@string/image_button_delete"
      android:src="@android:drawable/ic_input_add" /&gt;
  
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p>Row.xml</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:layout_width="match_parent"
              android:layout_height="match_parent"&gt;
  
  &lt;TextView
      android:id="@+id/textView1"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignParentLeft="true"
      android:layout_alignParentTop="true" /&gt;
  
  &lt;EditText
      android:id="@+id/unitEditText"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignParentLeft="true"
      android:layout_below="@+id/textView1"
      android:ems="10"
      android:inputType="numberDecimal" &gt;
  
      &lt;requestFocus /&gt;
  &lt;/EditText&gt;
  
  &lt;Spinner
      android:id="@+id/unitSpinner"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignBottom="@+id/imageButton1"
      android:layout_marginBottom="15dp"
      android:layout_toRightOf="@+id/unitEditText" /&gt;
  
  &lt;ImageButton
      android:id="@+id/imageButton1"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignBottom="@+id/unitEditText"
      android:layout_alignParentRight="true"
  
      android:onClick="removeItem"
  
      android:contentDescription="@string/image_button_delete"
      android:src="@android:drawable/ic_menu_delete" /&gt;
  
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p>MainActivity...</p>
  
  <pre><code>public class MainActivity extends FragmentActivity implements
      ActionBar.TabListener {
  
  /**
   * The {@link android.support.v4.view.PagerAdapter} that will provide
   * fragments for each of the sections. We use a
   * {@link android.support.v4.app.FragmentPagerAdapter} derivative, which
   * will keep every loaded fragment in memory. If this becomes too memory
   * intensive, it may be best to switch to a
   * {@link android.support.v4.app.FragmentStatePagerAdapter}.
   */
  SectionsPagerAdapter mSectionsPagerAdapter;
  
  /**
   * The {@link ViewPager} that will host the section contents.
   */
  ViewPager mViewPager;
  
  
  @Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
  
      // Set up the action bar.
      final ActionBar actionBar = getActionBar();
      actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
  
      // Create the adapter that will return a fragment for each of the three
      // primary sections of the app.
      mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
  
      // Set up the ViewPager with the sections adapter.
      mViewPager = (ViewPager) findViewById(R.id.pager);
      mViewPager.setAdapter(mSectionsPagerAdapter);
  
      // When swiping between different sections, select the corresponding
      // tab. We can also use ActionBar.Tab#select() to do this if we have
      // a reference to the Tab.
      mViewPager
              .setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
                  @Override
                  public void onPageSelected(int position) {
                      actionBar.setSelectedNavigationItem(position);
                  }
              });
  
      // For each of the sections in the app, add a tab to the action bar.
      for (int i = 0; i &lt; mSectionsPagerAdapter.getCount(); i++) {
          // Create a tab with text corresponding to the page title defined by
          // the adapter. Also specify this Activity object, which implements
          // the TabListener interface, as the callback (listener) for when
          // this tab is selected.
          actionBar.addTab(actionBar.newTab()
                  .setText(mSectionsPagerAdapter.getPageTitle(i))
                  .setTabListener(this));
      }
  }
  
  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
      // Inflate the menu; this adds items to the action bar if it is present.
      getMenuInflater().inflate(R.menu.main, menu);
      return true;
  }
  
  @Override
  public void onTabSelected(ActionBar.Tab tab,
          FragmentTransaction fragmentTransaction) {
      // When the given tab is selected, switch to the corresponding page in
      // the ViewPager.
      mViewPager.setCurrentItem(tab.getPosition());
  }
  
  @Override
  public void onTabUnselected(ActionBar.Tab tab,
          FragmentTransaction fragmentTransaction) {
  }
  
  @Override
  public void onTabReselected(ActionBar.Tab tab,
          FragmentTransaction fragmentTransaction) {
  }
  
  /**
   * A {@link FragmentPagerAdapter} that returns a fragment corresponding to
   * one of the sections/tabs/pages.
   */
  public class SectionsPagerAdapter extends FragmentPagerAdapter {
  
      public SectionsPagerAdapter(FragmentManager fm) {
          super(fm);
      }
  
      @Override
      public Fragment getItem(int position) {
          // getItem is called to instantiate the fragment for the given page.
          // Return a DummySectionFragment (defined as a static inner class
          // below) with the page number as its lone argument.
          Fragment fragment = new DummySectionFragment();
          Bundle args = new Bundle();
          args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, position + 1);
          fragment.setArguments(args);
          return fragment;
      }
  
      @Override
      public int getCount() {
          // Show 4 total pages.
          return 4;
      }
  
      @Override
      public CharSequence getPageTitle(int position) {
          Locale l = Locale.getDefault();
          switch (position) {
          case 0:
              return getString(R.string.title_section1).toUpperCase(l);
          case 1:
              return getString(R.string.title_section2).toUpperCase(l);
          case 2:
              return getString(R.string.title_section3).toUpperCase(l);
          case 3:
              return getString(R.string.title_section4).toUpperCase(l);
          }
          return null;
      }
  }
  
  /**
   * A dummy fragment representing a section of the app, but that simply
   * displays dummy text.
   */
  public static class DummySectionFragment extends Fragment {
      /**
       * The fragment argument representing the section number for this
       * fragment.
       */
      ArrayList&lt;String&gt; myStringArray1 =  new ArrayList&lt;String&gt;();//new String[]{"Egzo","Eg","Egzona"};
      String[] myStringArray2 = new String[]{"aaa","bbb","ccc"};
      String[] myStringArray3 = new String[]{"ddd","eeee"};
      String[] myStringArray4 = new String[]{"Cia","ci","Ciao"};
      public static ArrayAdapter&lt;String&gt; adapter;
  
      public static final String ARG_SECTION_NUMBER = "section_number";
  
      public DummySectionFragment() {
      }
  
      @Override
      public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
          View rootView = inflater.inflate(R.layout.fragment_main_dummy,container, false);
          //TextView dummyTextView = (TextView) rootView.findViewById(R.id.section_label);
          //dummyTextView.setText(Integer.toString(getArguments().getInt(ARG_SECTION_NUMBER)));
  
          // ListView
          ListView unitListView = (ListView) rootView.findViewById(R.id.unitListView);
  
          switch(getArguments().getInt(ARG_SECTION_NUMBER)) {
          case 1:
              myStringArray1.add("mmm");
  
              adapter = new CustomAdapter(getActivity(), R.layout.row, myStringArray1);
              unitListView.setAdapter(adapter);
              break;
          case 2:
              adapter = new ArrayAdapter&lt;String&gt;(getActivity(), R.layout.row, R.id.textView1, myStringArray2);
              unitListView.setAdapter(adapter);
              break;
          case 3:
              adapter = new ArrayAdapter&lt;String&gt;(getActivity(), R.layout.row, R.id.textView1, myStringArray3);
              unitListView.setAdapter(adapter);
              break;
          case 4:
              adapter = new ArrayAdapter&lt;String&gt;(getActivity(), R.layout.row, R.id.textView1, myStringArray4);
              unitListView.setAdapter(adapter);
              break;
          }
          unitListView.setOnItemClickListener(listViewOnClickListener);
  
          // ImageButton
          ImageButton moreImageButton = (ImageButton) rootView.findViewById(R.id.moreImageButton);
          moreImageButton.setOnClickListener(moreListener);
  
  
          return rootView;
      }
  
      public OnClickListener moreListener = new OnClickListener(){
  
          @Override
          public void onClick(View v) {
              // TODO Auto-generated method stub
  
              myStringArray1.add("Andrea");
              adapter.clear();
              adapter.addAll(myStringArray1);
              adapter.notifyDataSetChanged();
          }
  
      };
  
      public OnItemClickListener listViewOnClickListener = new OnItemClickListener() {
  
          @Override
          public void onItemClick(AdapterView&lt;?&gt; arg0, View arg1, int arg2,
                  long arg3) {
              // TODO Auto-generated method stub
  
          }
  
      };
  }
  
  }
  </code></pre>
  
  <p>Note that I'm working only with the first tab right now...</p>
  
  <p>What am I doing wrong? :)</p>