andrew andrew - 1 month ago 15
Java Question

Add Items to ListView - Android

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.

I searched around, and I've always found

adapter.notifyDataSetChanged();


but doesn't work for me.

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.

my custom Adapter:

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<String> {
private final Context context;
private final int resourceID;

public CustomAdapter(Context context, int resource, ArrayList<String> 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;
}
}


fragment_main_dummy.xml

<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" >

<ListView
android:id="@+id/unitListView"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
</ListView>

<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" />

</RelativeLayout>


Row.xml

<?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">

<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true" />

<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" >

<requestFocus />
</EditText>

<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" />

<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" />

</RelativeLayout>


MainActivity...

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 < 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<String> myStringArray1 = new ArrayList<String>();//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<String> 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<String>(getActivity(), R.layout.row, R.id.textView1, myStringArray2);
unitListView.setAdapter(adapter);
break;
case 3:
adapter = new ArrayAdapter<String>(getActivity(), R.layout.row, R.id.textView1, myStringArray3);
unitListView.setAdapter(adapter);
break;
case 4:
adapter = new ArrayAdapter<String>(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<?> arg0, View arg1, int arg2,
long arg3) {
// TODO Auto-generated method stub

}

};
}

}


Note that I'm working only with the first tab right now...

What am I doing wrong? :)

Answer
ListView myListView = (ListView) rootView.findViewById(R.id.myListView);
ArrayList<String> myStringArray1 = new ArrayList<String>();
myStringArray1.add("something");
adapter = new CustomAdapter(getActivity(), R.layout.row, myStringArray1);
myListView.setAdapter(adapter);

Try it like this

public OnClickListener moreListener = new OnClickListener() {

    @Override
    public void onClick(View v) {
        adapter = null;
        myStringArray1.add("Andrea");
        adapter = new CustomAdapter(getActivity(), R.layout.row, myStringArray1);
        myListView.setAdapter(adapter);
        adapter.notifyDataSetChanged();
    }       
};