Question

In my android application I have checkboxes and on checking the checkboxes I want to set the visibility of the group element of ExpandableListView and also I want to set the title of group element to be the same as checkbox name.

 public void onCreate(Bundle savedInstanceState) {
    try{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.detailnewslist);

    SharedPreferences settings = getSharedPreferences("mysettings", MODE_WORLD_READABLE);
    boolean checkBoxValue1=settings.getBoolean("c1",false);
    boolean checkBoxValue2=settings.getBoolean("c2",false);
    /*if(checkBoxValue1==true)
    {
        t1.setText(settings.getString("checkbox", "null"));
    }else{t1.setVisibility(View.GONE);}
    if(checkBoxValue2==true){
        t2.setText(settings.getString("checkbox1", "null"));
    }else{t2.setVisibility(View.GONE);}
    */
     SimpleExpandableListAdapter expListAdapter =
            new SimpleExpandableListAdapter(
                    this,
                    createGroupList(),              // Creating group List.
                    R.layout.group_row,             // Group item layout XML.           
                    new String[] { "Group Item" },  // the key of group item.
                    new int[] { R.id.row_name },    // ID of each group item.-Data under the key goes into this TextView.                   
                    createChildList(),              // childData describes second-level entries.
                    R.layout.child_row,             // Layout for sub-level entries(second level).
                    new String[] {"Sub Item"},      // Keys in childData maps to display.
                    new int[] { R.id.grp_child}     // Data under the keys above go into these TextViews.
                );
            setListAdapter( expListAdapter );       // setting the adapter in the list.

        }catch(Exception e){
            System.out.println("Errrr +++ " + e.getMessage());
        }
    }

    /* Creating the Hashmap for the row */
    @SuppressWarnings("unchecked")
    private List createGroupList() {

          ArrayList result = new ArrayList();
          for( int i = 1 ; i < 16 ; ++i ) { // 15 groups........
            HashMap m = new HashMap();
            m.put( "Group Item","Group I " + i ); // the key and it's value.
            result.add( m );
          }
          return (List)result;
    }

    /* creatin the HashMap for the children */
    @SuppressWarnings("unchecked")
    private List createChildList() {

        ArrayList result = new ArrayList();
        for( int i = 1 ; i < 16 ; ++i ) { // this -15 is the number of groups(Here it's fifteen)
          /* each group need each HashMap-Here for each group we have 3 subgroups */
          ArrayList secList = new ArrayList(); 
          for( int n = 0 ; n < 5 ; n++ ) {
            HashMap child = new HashMap();
            child.put( "Sub Item", "Sub Item " + n );           
            secList.add( child );
          }
         result.add( secList );
        }        
        return result;
    }
    public void  onContentChanged  () {
        System.out.println("onContentChanged");
        super.onContentChanged();         
    }
    /* This function is called on each child click */
    public boolean onChildClick( ExpandableListView parent, View v, int groupPosition,int childPosition,long id) {
        System.out.println("Inside onChildClick at groupPosition = " + groupPosition +" Child clicked at position " + childPosition);
        return true;
    }

    /* This function is called on expansion of the group */
    public void  onGroupExpand  (int groupPosition) {
        try{
             System.out.println("Group exapanding Listener => groupPosition = " + groupPosition);
        }catch(Exception e){
            System.out.println(" groupPosition Errrr +++ " + e.getMessage());
        }
} 

Answer 1

The key method in ExpandableListView is:

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

See how it is implemented, for example, to show/hide the disclosure when there are no children.