Java 为什么建议列表在GWT中仍然可见

我正在gwt中使用建议框，并将SelectionHandler和onFocusHandler添加到建议框中，但选择后建议列表仍然可见。。但事实并非如此

选择一个建议后，我应该如何隐藏建议列表

suggestBox.getValueBox().addFocusHandler(new FocusHandler() {
        @Override
        public void onFocus(FocusEvent event) {
            if(suggestBox.getText().equals("")){
                suggestBox.setText(" ");
                suggestBox.showSuggestionList();
                suggestBox.setText("");
            }   
        }
    });

suggestBox.addSelectionHandler(new SelectionHandler<SuggestOracle.Suggestion>() {

        @Override
        public void onSelection(SelectionEvent<Suggestion> arg0) {
            if (arg0.getSelectedItem() instanceof Suggestion) {
                //code to take actions after selection
            }
        }
    });

suggestBox.getValueBox（）.addFocusHandler（新的FocusHandler（）{
@凌驾
公众焦点无效（焦点事件）{
if（suggestBox.getText（）.equals（“”）{
suggestBox.setText（“”）；
showSuggestionList（）；
suggestBox.setText（“”）；
}   
}
});
suggestBox.addSelectionHandler（新的SelectionHandler（）{
@凌驾
选择时公共无效（SelectionEvent arg0）{
if（arg0.getSelectedItem（）建议实例）{
//选择后执行操作的代码
}
}
});

选择其中一项后，我应该如何隐藏建议列表 建议

suggestBox.getValueBox().addFocusHandler(new FocusHandler() {
        @Override
        public void onFocus(FocusEvent event) {
            if(suggestBox.getText().equals("")){
                suggestBox.setText(" ");
                suggestBox.showSuggestionList();
                suggestBox.setText("");
            }   
        }
    });

suggestBox.addSelectionHandler(new SelectionHandler<SuggestOracle.Suggestion>() {

        @Override
        public void onSelection(SelectionEvent<Suggestion> arg0) {
            if (arg0.getSelectedItem() instanceof Suggestion) {
                //code to take actions after selection
            }
        }
    });

为什么不在选择处理程序中隐藏列表

    @Override
    public void onSelection(SelectionEvent<Suggestion> arg0) {
        if (arg0.getSelectedItem() instanceof Suggestion) {
            //code to take actions after selection
        }
        DefaultSuggestionDisplay display = (DefaultSuggestionDisplay) suggestBox.getSuggestionDisplay();
        display.hideSuggestions();
    }

@覆盖
选择时公共无效（SelectionEvent arg0）{
if（arg0.getSelectedItem（）建议实例）{
//选择后执行操作的代码
}
DefaultSuggestionDisplay=（DefaultSuggestionDisplay）suggestBox.getSuggestionDisplay（）；
display.hideSuggestions（）；
}

通过添加问题的代码段来更新问题。焦点处理程序应该做什么？我打赌有更好的办法。