Android-列表项目不会在具有自定义列表适配器的双窗格详细信息/流程中激活

Question

我正在使用Eclipse中的Master详细信息流模板，其中包含一个显示图像和3个文本的自定义列表适配器：

public class CustomAdapter extends BaseAdapter {

    private Activity activity;
    private ArrayList<HashMap<String,String>> data;  
    private static LayoutInflater inflater=null;
    public ImageLoader imageLoader;//I have a class for loading images

    public CustomAdapter(Activity a, ArrayList<HashMap<String, String>> d) {
        activity = a;
        data = d;
        inflater = (LayoutInflater)activity.getSystemService(
                      Context.LAYOUT_INFLATER_SERVICE);
        imageLoader = new ImageLoader(activity.getApplicationContext());
    }

    public int getCount() {
        return data.size();
    }

    public Object getItem(int position) {
        return position;
    }

    public long getItemId(int position) {
        return position;
    }

    public View getView(int position, View convertView, ViewGroup parent) {
        View vi = convertView;
        if(convertView == null)
            vi = inflater.inflate(R.layout.list_row, null);

        TextView text1 = (TextView) vi.findViewById(R.id.text1); 
        TextView text2 = (TextView) vi.findViewById(R.id.text2); 
        TextView text3 = (TextView) vi.findViewById(R.id.text3); 
        ImageView image= (ImageView) vi.findViewById(R.id.image); 

        HashMap<String, String> tap = new HashMap<String, String>();
        tap = data.get(position);

        // Setting all values in listview
        text1.setText("item1");
        text2.setText("item2");
        text3.setText("item3");
        imageLoader.DisplayImage(R.drawable.display_image,
                               R.drawable.loading_image, image);
        return vi;
    }
}

方法setActiveOnItemClick()在ItemListFragment类中未更改，并且在双窗格模式下从ItemListActivity类调用此方法，就像在模板中一样。但是，在双窗格模式下单击时，列表项不会被赋予“激活”状态。为什么这样，我该如何解决？