GWT：标签到列表框

Question

我在GWT中有一个列表框。下拉菜单中有各种项目。 我想为列表框设置一个标签。并将其移动到正确的方向。 任何人都可以帮忙。

@Override
    public void onWindowFocusChanged(boolean hasFocus) {

        int[] location = new int[2];
        TextView button = (TextView) findViewById(R.id.textView2);

        // Get the x, y location and store it in the location[] array
        // location[0] = x, location[1] = y.
        button.getLocationOnScreen(location);

        //Initialize the Point with x, and y positions
        p = new Point();
        p.x = location[0];
        p.y = location[1];
    }

    //............
    private void showPopup(final Activity context, Point p) {


        // Inflate the popup_layout.xml
        LinearLayout viewGroup = (LinearLayout) context.findViewById(R.id.popup);
        LayoutInflater layoutInflater = (LayoutInflater) context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View layout = layoutInflater.inflate(R.layout.popup, viewGroup);

        // Creating the PopupWindow
        final PopupWindow popup = new PopupWindow(context);
        popup.setContentView(layout);
        popup.setWindowLayoutMode(ViewGroup.LayoutParams.WRAP_CONTENT,
                ViewGroup.LayoutParams.WRAP_CONTENT);
        popup.setFocusable(true);

        // Some offset to align the popup a bit to the right, and a bit down, relative to button's position.
        int OFFSET_X = 30;
        int OFFSET_Y = 30;

        // Clear the default translucent background
        popup.setBackgroundDrawable(new BitmapDrawable());

        // Displaying the popup at the specified location, + offsets.
        popup.showAtLocation(layout, Gravity.NO_GRAVITY, p.x + OFFSET_X, p.y + OFFSET_Y);

        // Getting a reference to Close button, and close the popup when clicked.
        TextView close = (TextView) layout.findViewById(R.id.textView37);
        close.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                popup.dismiss();
            }
        });
    }

如何在此列表框中添加标签。 如果我使用下面的代码。对齐不正确。

private ListBox makeCalculationMethodField(List<String> cList) {
    ListBox dropBox = new ListBox();
    dropBox.setVisibleItemCount(0);
     for (String name : cList) {
         dropBox.addItem(name);
          }
    return dropBox;
}