问在XML文件中使用字符串数组的可扩展列表视图

EN

 public class ExpandableList1 extends ExpandableListActivity {

    ExpandableListAdapter mAdapter;

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

        // Set up our adapter
        mAdapter = new MyExpandableListAdapter();
        setListAdapter(mAdapter);
        registerForContextMenu(getExpandableListView());
    }

    @Override
    public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) {
        menu.setHeaderTitle("Sample menu");
        menu.add(0, 0, 0, R.string.expandable_list_sample_action);
    }

    @Override
    public boolean onContextItemSelected(MenuItem item) {
        ExpandableListContextMenuInfo info = (ExpandableListContextMenuInfo) item.getMenuInfo();

        String title = ((TextView) info.targetView).getText().toString();

        int type = ExpandableListView.getPackedPositionType(info.packedPosition);
        if (type == ExpandableListView.PACKED_POSITION_TYPE_CHILD) {
            int groupPos = ExpandableListView.getPackedPositionGroup(info.packedPosition); 
            int childPos = ExpandableListView.getPackedPositionChild(info.packedPosition); 
            Toast.makeText(this, title + ": Child " + childPos + " clicked in group " + groupPos,
                    Toast.LENGTH_SHORT).show();
            return true;
        } else if (type == ExpandableListView.PACKED_POSITION_TYPE_GROUP) {
            int groupPos = ExpandableListView.getPackedPositionGroup(info.packedPosition); 
            Toast.makeText(this, title + ": Group " + groupPos + " clicked", Toast.LENGTH_SHORT).show();
            return true;
        }

        return false;
    }


    public class MyExpandableListAdapter extends BaseExpandableListAdapter {
        // Sample data set.  children[i] contains the children (String[]) for groups[i].
        private String[] groups = getResources().getStringArray(R.array.countries);
        private String[][] children =  {getResources().getStringArray(R.array.asianCountries),
               getResources().getStringArray(R.array.africanCountries),getResources().getStringArray(R.array.europeanCountries)};





        public Object getChild(int groupPosition, int childPosition) {
            return children[groupPosition][childPosition];
        }

        public long getChildId(int groupPosition, int childPosition) {
            return childPosition;
        }

        public int getChildrenCount(int groupPosition) {
            return children[groupPosition].length;
        }

        public TextView getGenericView() {
            // Layout parameters for the ExpandableListView
            AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
                    ViewGroup.LayoutParams.MATCH_PARENT, 64);

            TextView textView = new TextView(ExpandableList1.this);
            textView.setLayoutParams(lp);
            // Center the text vertically
            textView.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);
            // Set the text starting position
            textView.setPadding(55, 0, 0, 0);
            return textView;
        }

        public View getChildView(int groupPosition, int childPosition, boolean isLastChild,
                View convertView, ViewGroup parent) {
            TextView textView = getGenericView();
            textView.setText(getChild(groupPosition, childPosition).toString());
            return textView;
        }

        public Object getGroup(int groupPosition) {
            return groups[groupPosition];
        }

        public int getGroupCount() {
            return groups.length;
        }

        public long getGroupId(int groupPosition) {
            return groupPosition;
        }

        public View getGroupView(int groupPosition, boolean isExpanded, View convertView,
                ViewGroup parent) {
            TextView textView = getGenericView();
            textView.setText(getGroup(groupPosition).toString());
            return textView;
        }

        public boolean isChildSelectable(int groupPosition, int childPosition) {
            return true;
        }

        public boolean hasStableIds() {
            return true;
        }

    }
}