在添加我的数据源之后将Item添加到selectItem

Question

I'm trying to add one option per default in my selectItem, it has binding one datasource and after do that i try to add one option per default. My problem is that i always see the items in the datasource but never my default option. Those are my lines of code :

Option 1

LinkedHashMap<String, String> valueMap= new LinkedHashMap<String, String>();
valueMap.put("null","null3");
branchSelectionItem.setValueMap(valueMap);

Option 2

Record rec = new Record();
rec.setAttribute("Name","asdad");
branchDs.addData(rec);
branchSelectionItem.setOptionDataSource(branchDs);

I used to methods first one try to add with valueMap option and the second one is add one record to my datasource, but any of them works. Any Idea ?

thanks a lot!!

Answer 1

好的，我解决了这个问题，再次为默认添加了一个空值供选择。

 branchSelectionItem.setAllowEmptyValue(true);