easyui-combobox默认值绑定

  $('#combox_role').combobox({
      panelHeight: ,
      url: '../../Handler/GetComboxItems.ashx?type=0',
      valueField: 'RoleId',
      textField: 'RoleName',
      onLoadSuccess: function () {
          var oData = $(this).combobox('getData');
          for (var item in oData[]) {
              if (item == "RoleId") {
                  $(this).combobox("select", oData[][item]);
              }
          }
      }
  });

还可以通过下面的方式绑定默认值