How do i get the state of a pair of RadioButtons, in a RadioGroup, in a ListView?

Question

I have a list-view with a custom list row. In each list-view's row, there is a Radio-group with 2 Radio-buttons.

I need to know the state of the RadioButtons, for each row of the ListView (checked or not), dynamically, as the user click on one of the RadioGroup's options.

My main xml:

<?xml version="1.0" encoding="utf-8"?>
<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:background="#fff3f2f2"
    android:orientation="horizontal" >

    <RelativeLayout
        android:id="@+id/header"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:background="#00ffffff"
        android:gravity="center" >

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="#00ffffff"
            android:gravity="center_horizontal"
            android:paddingBottom="10dp"
            android:paddingTop="10dp"
            android:text="@string/titulo_cabecalho"
            android:textColor="#ff000000"
            android:textSize="36sp" >
        </TextView>
    </RelativeLayout>

    <!-- Footer aligned to top -->

    <include layout="@layout/footer" />

    <RelativeLayout
        android:id="@+id/selectEscola"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@id/footer"
        android:layout_below="@id/header"
        android:layout_centerInParent="true"
        android:layout_marginBottom="10dp"
        android:layout_marginTop="4dp"
        android:background="#00ffffff"
        android:orientation="vertical" >

        <TextView
            android:id="@+id/textView1"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:text="Chamada"
            android:textAppearance="?android:attr/textAppearanceMedium"
            android:textColor="#c0000000" />

        <ScrollView
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_marginTop="80dp"
            android:layout_marginBottom="80dp"
            android:scrollbars="none"
            android:background="@drawable/border" >

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:orientation="vertical" >

                <ListView
                    android:id="@+id/listChamada"
                    android:layout_width="wrap_content"
                    android:layout_height="0dip"
                    android:layout_weight="1"
                    android:divider="#b5b5b5"
                    android:dividerHeight="1dp"
                    android:listSelector="@drawable/list_selector"
                    android:padding="2dp" />
            </LinearLayout>
        </ScrollView>
    </RelativeLayout>

</RelativeLayout>

My custom row is:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:descendantFocusability="blocksDescendants"
    android:orientation="horizontal"
    android:padding="2dip"
    android:background="@drawable/border2" >

    <LinearLayout
        android:id="@+id/thumbnail"
        android:layout_width="wrap_content"
        android:layout_height="34dip"
        android:layout_alignParentLeft="true"
        android:layout_marginRight="5dip"
        android:padding="3dip"
        android:orientation="horizontal" >

        <ImageView
            android:id="@+id/listEdit"
            android:layout_width="24dip"
            android:layout_height="24dip"
            android:layout_marginTop="2dip"
            android:src="@drawable/list" />

        <ImageView
            android:id="@+id/list_image"
            android:layout_width="24dip"
            android:layout_height="24dip"
            android:layout_marginLeft="20dip"
            android:layout_marginTop="2dip"
            android:src="@drawable/boy" />
    </LinearLayout>


    <TextView
        android:id="@+id/nomealuno"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/matriculaaluno"
        android:layout_alignTop="@+id/thumbnail"
        android:text="Nome:"
        android:textColor="#040404"
        android:textSize="18sp"
        android:textStyle="bold"
        android:typeface="sans" />

    <TextView
        android:id="@+id/matriculaaluno"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/nomealuno"
        android:layout_marginTop="2dp"
        android:layout_toRightOf="@+id/thumbnail"
        android:text="Matrícula: "
        android:textColor="#343434"
        android:textSize="10sp" />

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_marginRight="4dp"
        android:orientation="vertical" >

        <RadioGroup
            android:id="@+id/radiogroupChamada"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="horizontal"
            android:textColor="#343434"
            android:textSize="12sp"
            android:textStyle="bold" >

            <RadioButton
                android:id="@+id/radiobuttonPresente"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:button="@null"
                android:drawableRight="@drawable/btn_check"
                android:paddingLeft="22dip"
                android:text="Presente" >
            </RadioButton>

            <RadioButton
                android:id="@+id/radiobuttonAusente"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:button="@null"
                android:drawableRight="@drawable/btn_check"
                android:paddingLeft="22dip"
                android:text="Ausente" >
            </RadioButton>
        </RadioGroup>
    </LinearLayout>

</RelativeLayout>

This is how I populate the ListView:

1 - Code to put the data received from server received in Json format, in arrays and hashmap (I use the arrays to have a reference to the data present in the ListView and hashmap to populate it) :

if (success2 == 1) // If data from server was sent without errors
{
    int lenght = jArray.length();
    optionsMatriculas = new ArrayList<String>(lenght);
    optionsNomesAlunos = new ArrayList<String>(lenght);
    optionsSexoAlunos = new ArrayList<String>(lenght);

    for (int i = 0; i < jArray.length(); i++)
    {
        try
        {
            JSONObject oneObject = jArray.getJSONObject(i);
            resultDataCodigoAluno = oneObject.getString("cdaluno");
            resultDataNomes = oneObject.getString("nome");
            resultDataSexo = oneObject.getString("sexo");

            optionsMatriculas.add(resultDataCodigoAluno);
            optionsNomesAlunos.add(resultDataNomes);
            optionsSexoAlunos.add(resultDataSexo);

            HashMap<String, String> hm = new HashMap<String, String>();

            if (resultDataSexo.equals("M"))
            {
                hm.put("sexo", Integer.toString(R.drawable.boy));
            }
            else
            {
                hm.put("sexo", Integer.toString(R.drawable.girl));
            }

            hm.put("matricula", resultDataCodigoAluno);
            hm.put("nome", resultDataNomes);

            alunosLista.add(hm);

        }
        catch (JSONException e)
        {
            Log.e("log_tag", "Error in parsing JSon: " + e.toString());
        }
    }

    Message msg = myHandler.obtainMessage();
    myHandler.sendMessage(msg);
}

This is the code to populate the listview:

final Handler myHandler = new Handler()
{
    @Override
    public void handleMessage(Message msg)
    {
        try
        {
            SimpleAdapter adapter = new SimpleAdapter(getBaseContext(), alunosLista, R.layout.list_row, from, to);
            listaChamada.setAdapter(adapter);

            int lenght = adapter.getCount();
            int totalHeight = 0;

            for (int i = 0; i < lenght; i++)
            {
                View listItem = adapter.getView(i, null, listaChamada);
                listItem.measure(0, 0);
                totalHeight += listItem.getMeasuredHeight();
            }

            ViewGroup.LayoutParams params = listaChamada.getLayoutParams();
            params.height = totalHeight + 4 + (listaChamada.getDividerHeight() * (adapter.getCount() - 1));
            listaChamada.setLayoutParams(params);
            listaChamada.requestLayout();                   
        }
        catch (Exception e)
        {
            Log.e("log_tag", "Erro no ListView: " + e.toString());
        }
    }//handleMessage 
};//myHandler 

I have searched, in Google, but still no luck. Thanks for any clue about this.

Answer 1

Actually, Android adapters is not that simple. SimpleAdapter can be applied only in some very simple/trivial cases. Usually, it's preferred to create own BaseAdapter: it gives much more flexibility and doesn't require lot of code. In your case I would suggest to use smth like the following (You failed to provide any information about that is from and to in your SimpleAdapter constructor, so I guessed):

Main part is proper adapter, which should store selected radio button id and provide it back to the activity/receiver.

MyAdapter.java

public class MyActivity extends Activity implements MyListAdapter.RadioButtonsListener {

    private static final String TAG = "MyActivity";

    ArrayList<HashMap<String, String>> mAlunosLista = new ArrayList<HashMap<String, String>>();


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        final ListView listaChamada = (ListView) findViewById(R.id.listChamada);
        // Fill list with data
        Random sexGen = new Random();

        for (int i = 0; i < 20; i++) {
            addTextData(sexGen.nextBoolean() ? "M" : "F", Integer.toString(i + 100), "Name" + i + " Surname" + i);
        }

        final MyListAdapter adapter = new MyListAdapter(mAlunosLista);

        listaChamada.setAdapter(adapter);
    }

    @Override
    protected void onResume() {
        super.onResume();

        final MyListAdapter adapter = (MyListAdapter) ((ListView) findViewById(R.id.listChamada)).getAdapter();

        adapter.setRadioListener(this);
    }

    @Override
    protected void onPause() {
        super.onPause();

        final MyListAdapter adapter = (MyListAdapter) ((ListView) findViewById(R.id.listChamada)).getAdapter();

        adapter.setRadioListener(null);
    }

    /**
     * Adds test data to adapter array
     */
    private void addTextData(final String resultDataSexo, final String resultDataCodigoAluno, final String resultDataNomes) {
        HashMap<String, String> hm = new HashMap<String, String>();

        // NOTE: not sure why you convert ids to strings
        if (resultDataSexo.equals("M")) {
            hm.put("sexo", Integer.toString(R.drawable.boy));
        } else {
            hm.put("sexo", Integer.toString(R.drawable.girl));
        }

        hm.put("matricula", resultDataCodigoAluno);
        hm.put("nome", resultDataNomes);

        mAlunosLista.add(hm);
    }

    @Override
    public void onRadioButtonClicked(final int position, final HashMap<String, String> itemData, final int clickedId) {
        Log.d(TAG, "Clicked item at " + position + ", checked id: " + (clickedId == R.id.radiobuttonPresente ? "Presente" : "Ausente"));
    }
}

Below other files I've changed to have compilable example (please refer help topic on how to ask questions about code questions body).

main.xml

<?xml version="1.0" encoding="utf-8"?>

<!--suppress AndroidLintUselessParent, AndroidLintContentDescription -->
<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:background="#fff3f2f2"
    android:orientation="horizontal" >

    <RelativeLayout
        android:id="@+id/header"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:background="#00ffffff"
        android:gravity="center" >

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="#00ffffff"
            android:gravity="center_horizontal"
            android:paddingBottom="10dp"
            android:paddingTop="10dp"
            android:text="Title"
            android:textColor="#ff000000"
            android:textSize="36sp" >
        </TextView>
    </RelativeLayout>

    <!-- Footer aligned to top

    <include layout="@layout/footer" />
    -->
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/footer"
        android:layout_alignParentBottom="true" />

    <RelativeLayout
        android:id="@+id/selectEscola"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_above="@id/footer"
        android:layout_below="@id/header"
        android:layout_centerInParent="true"
        android:layout_marginBottom="10dp"
        android:layout_marginTop="4dp"
        android:background="#00ffffff"
        android:orientation="vertical" >

        <TextView
            android:id="@+id/textView1"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:text="Chamada"
            android:textAppearance="?android:attr/textAppearanceMedium"
            android:textColor="#c0000000" />

        <ListView
            android:id="@+id/listChamada"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:divider="#b5b5b5"
            android:dividerHeight="1dp"
            android:listSelector="@android:drawable/list_selector_background"
            android:padding="2dp" />
    </RelativeLayout>

</RelativeLayout>

list_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="wrap_content"
    android:descendantFocusability="blocksDescendants"
    android:orientation="horizontal"
    android:padding="2dip"
    android:background="@android:color/darker_gray" >

    <LinearLayout
        android:id="@+id/thumbnail"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginRight="5dip"
        android:padding="3dip"
        android:orientation="horizontal" >

        <ImageView
            android:id="@+id/listEdit"
            android:layout_width="24dip"
            android:layout_height="24dip"
            android:layout_marginTop="2dip"
            android:src="@android:drawable/ic_menu_add" />

        <ImageView
            android:id="@+id/list_image"
            android:layout_width="24dip"
            android:layout_height="24dip"
            android:layout_marginLeft="20dip"
            android:layout_marginTop="2dip"
            android:src="@android:drawable/ic_delete" />
    </LinearLayout>

    <TextView
        android:id="@+id/nomealuno"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/matriculaaluno"
        android:layout_alignTop="@+id/thumbnail"
        android:text="Nome:"
        android:textColor="#040404"
        android:textSize="18sp"
        android:textStyle="bold"
        android:typeface="sans" />

    <TextView
        android:id="@+id/matriculaaluno"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/nomealuno"
        android:layout_marginTop="2dp"
        android:layout_toRightOf="@+id/thumbnail"
        android:text="Matrícula: "
        android:textColor="#343434"
        android:textSize="10sp" />

    <RadioGroup
        android:id="@+id/radiogroupChamada"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/thumbnail"
        android:orientation="vertical"
        android:textColor="#343434"
        android:textSize="12sp"
        android:textStyle="bold" >

        <RadioButton
            android:id="@+id/radiobuttonPresente"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:paddingLeft="22dip"
            android:text="Presente" />
        <!--android:drawableRight="@drawable/btn_check"-->

        <RadioButton
            android:id="@+id/radiobuttonAusente"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:paddingLeft="22dip"
            android:text="Ausente" />
        <!--android:drawableRight="@drawable/btn_check"-->
    </RadioGroup>

</RelativeLayout>

MyActivity.java

public class MyActivity extends Activity implements MyListAdapter.RadioButtonsListener {

    private static final String TAG = "MyActivity";

    ArrayList<HashMap<String, String>> mAlunosLista = new ArrayList<HashMap<String, String>>();


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        final ListView listaChamada = (ListView) findViewById(R.id.listChamada);
        // Fill list with data
        Random sexGen = new Random();

        for (int i = 0; i < 20; i++) {
            addTextData(sexGen.nextBoolean() ? "M" : "F", Integer.toString(i + 100), "Name" + i + " Surname" + i);
        }

        final MyListAdapter adapter = new MyListAdapter(mAlunosLista);

        listaChamada.setAdapter(adapter);
    }

    @Override
    protected void onResume() {
        super.onResume();

        final MyListAdapter adapter = (MyListAdapter) ((ListView) findViewById(R.id.listChamada)).getAdapter();

        adapter.setRadioListener(this);
    }

    @Override
    protected void onPause() {
        super.onPause();

        final MyListAdapter adapter = (MyListAdapter) ((ListView) findViewById(R.id.listChamada)).getAdapter();

        adapter.setRadioListener(null);
    }

    /**
     * Adds test data to adapter array
     */
    private void addTextData(final String resultDataSexo, final String resultDataCodigoAluno, final String resultDataNomes) {
        HashMap<String, String> hm = new HashMap<String, String>();

        // NOTE: not sure why you convert ids to strings
        if (resultDataSexo.equals("M")) {
            hm.put("sexo", Integer.toString(R.drawable.boy));
        } else {
            hm.put("sexo", Integer.toString(R.drawable.girl));
        }

        hm.put("matricula", resultDataCodigoAluno);
        hm.put("nome", resultDataNomes);

        mAlunosLista.add(hm);
    }

    @Override
    public void onRadioButtonClicked(final int position, final HashMap<String, String> itemData, final int clickedId) {
        Log.d(TAG, "Clicked item at " + position + ", checked id: " + (clickedId == R.id.radiobuttonPresente ? "Presente" : "Ausente"));

} }

PS Also, it looks like You're trying to make some hack to ListView. I have no idea why do You need it here, but it's better to avoid until completely necessary.