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Jayden Bell
Jayden Bell

Total Post:105

Points:739
Posted on    October-17-2014 12:02 AM

 Android Android 
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I have an expandable list view. I use a custom adapter to load my own .xml layout. Each group has a Switch. I don't know how many groups will be displayed. Now I am wondering how to dynamically add a listener to each switch, in order to react on changes.

ExpandableListView Activity:

    public class ExpandableListView extends Activity {

    private MyCustomAdapter adapter;
    private ExpandableListView listView;

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

        setContentView(R.layout.detail_layout); 

        initViews();        
    }   

    private void initViews() {

        listView = (ExpandableListView) findViewById(R.id.foo);
        adapter = new MyCustomAdapter(this, data); // my custom adapter
        listView.setAdapter(adapter);

        //...   
    }

    //...   
}
MyCustomAdapter

public class MyCustomAdapter extends BaseExpandableListAdapter {

    @Override
    public View getGroupView(int groupPosition, boolean isExpanded,
            View convertView, ViewGroup parent) {

        String headerTitle = (String) getGroup(groupPosition);
        if (convertView == null) {
            LayoutInflater infalInflater = (LayoutInflater) this.context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = infalInflater.inflate(R.layout.list_group, null); // load layout with switch
        }

        TextView lblListHeader = (TextView) convertView
                .findViewById(R.id.myTextView;
        lblListHeader.setTypeface(null, Typeface.BOLD);
        lblListHeader.setText(headerTitle);

        return convertView;
    }

    // ...
}

list_group.xml

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

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="fill_parent"

    android:layout_height="wrap_content"

    android:padding="8dp"

    android:background="#000000">

 

 

    <TextView

        android:id="@+id/myTextView"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_alignParentLeft="true"

        android:layout_alignParentStart="true"

        android:paddingLeft="20dp"

        android:paddingRight="0dp"

        android:paddingEnd="0dp"

        android:paddingStart="20dp"

        android:textSize="17sp" />

 

 

    <Switch

        android:id="@+id/mySwitch"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_alignParentRight="true"

        android:layout_alignParentEnd="true"

        android:focusable="false"

        android:checked="true"

     />

 

 

</RelativeLayout>

How can I add a listener to each "mySwitch"? Is this possible in ExpandableListView ?



Mark Devid
Mark Devid

Total Post:101

Points:707
Posted on    October-17-2014 12:03 AM

Add a listener when inflating the group layout. And you can distinguish which group's switch was clicked by setting a tag that corresponds to that group position.

 Here's an example:


@Override

public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {

    if (convertView == null) {

        ...

 

        // Add a switch listener

        Switch mySwitch = (Switch) convertView.findViewById(R.id.mySwitch);

        mySwitch.setTag(groupPosition);

        mySwitch.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {

            @Override

            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {

                Log.e("TAG", "Clicked position: " + buttonView.getTag());

            }

        });

    } else {

        convertView.findViewById(R.id.mySwitch).setTag(groupPosition);

    }

 

    ...

 

    return convertView;

}

Note that you need to set the tag each time getGroupView is called.

 

As a sidenote: you should use a Holder pattern so you don't have to call findViewById (which is costly) in getGroupView.

 


Modified On Jun-26-2016 11:05:52 PM

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