kittu88 kittu88 - 6 months ago 29
Java Question

Onclick listner to expandable listview

I have created an expandable listview, but the onclick listener to the child list items could not be attached.

The activity code:

public class MyActivity extends Activity {

private ExpandableListView mExpandableList;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);


mExpandableList = (ExpandableListView)findViewById(R.id.expandable_list);

ArrayList<Parent> arrayParents = new ArrayList<Parent>();
ArrayList<String> arrayChildren = new ArrayList<String>();

//here we set the parents and the children
for (int i = 0; i < 2; i++){
//for each "i" create a new Parent object to set the title and the children
Parent parent = new Parent();
parent.setTitle("Parent " + i);

arrayChildren = new ArrayList<String>();
for (int j = 0; j < 3; j++) {
arrayChildren.add("Child " + j);
}
parent.setArrayChildren(arrayChildren);

//in this array we add the Parent object. We will use the arrayParents at the setAdapter
arrayParents.add(parent);
}

//sets the adapter that provides data to the list.
mExpandableList.setAdapter(new MyCustomAdapter(MyActivity.this,arrayParents));

}

}


The custom adapter for the lists:

public class MyCustomAdapter extends BaseExpandableListAdapter {


private LayoutInflater inflater;
private ArrayList<Parent> mParent;

public MyCustomAdapter(Context context, ArrayList<Parent> parent){
mParent = parent;
inflater = LayoutInflater.from(context);
}


@Override
//counts the number of group/parent items so the list knows how many times calls getGroupView() method
public int getGroupCount() {
return mParent.size();
}

@Override
//counts the number of children items so the list knows how many times calls getChildView() method
public int getChildrenCount(int i) {
return mParent.get(i).getArrayChildren().size();
}

@Override
//gets the title of each parent/group
public Object getGroup(int i) {
return mParent.get(i).getTitle();
}

@Override
//gets the name of each item
public Object getChild(int i, int i1) {
return mParent.get(i).getArrayChildren().get(i1);
}

@Override
public long getGroupId(int i) {
return i;
}

@Override
public long getChildId(int i, int i1) {
return i1;
}

@Override
public boolean hasStableIds() {
return true;
}

@Override
//in this method you must set the text to see the parent/group on the list
public View getGroupView(int i, boolean b, View view, ViewGroup viewGroup) {

if (view == null) {
view = inflater.inflate(R.layout.list_item_parent, viewGroup,false);
}

TextView textView = (TextView) view.findViewById(R.id.list_item_text_view);
//"i" is the position of the parent/group in the list
textView.setText(getGroup(i).toString());

//return the entire view
return view;
}

@Override
//in this method you must set the text to see the children on the list
public View getChildView(int i, int i1, boolean b, View view, ViewGroup viewGroup) {
if (view == null) {
view = inflater.inflate(R.layout.list_item_child, viewGroup,false);
}

TextView textView = (TextView) view.findViewById(R.id.list_item_text_child);
//"i" is the position of the parent/group in the list and
//"i1" is the position of the child
textView.setText(mParent.get(i).getArrayChildren().get(i1));

//return the entire view
return view;
}

@Override
public boolean isChildSelectable(int i, int i1) {
return true;
}

@Override
public void registerDataSetObserver(DataSetObserver observer) {
/* used to make the notifyDataSetChanged() method work */
super.registerDataSetObserver(observer);
}
}


The parent class:

public class Parent {
private String mTitle;
private ArrayList<String> mArrayChildren;

public String getTitle() {
return mTitle;
}

public void setTitle(String mTitle) {
this.mTitle = mTitle;
}

public ArrayList<String> getArrayChildren() {
return mArrayChildren;
}

public void setArrayChildren(ArrayList<String> mArrayChildren) {
this.mArrayChildren = mArrayChildren;
}

}


What should I do to add onclick listener to the child list items?

SKK SKK
Answer

Add this after you setAdapter of the Expandable list

mExpandableList.setOnChildClickListener(new OnChildClickListener() {

   @Override
   public boolean onChildClick(ExpandableListView parent, View v,int groupPosition, int childPosition, long id) {

      /* You must make use of the View v, find the view by id and extract the text as below*/

      TextView tv= (TextView) v.findViewById(R.id.childTextView);

      String data= tv.getText().toString();                 

      return true;  // i missed this
    }
});