Why do I receive a warning when I repopulate my "listbox" uicontrol in MATLAB?

I create a "listbox" uicontrol which contains two items:

hListBox = uicontrol('Style','listbox','String',{'item 1' 'item 2'},'Position',[20 20 100 200]);

I select the listbox item 2, and then I repopulate the listbox with a single entry:

set(hListBox,'String',{'new item'});

When I repopulate my listbox, I receive a warning:

 Warning: single-selection listbox control requires that Value be an integer within String range

 Control will not be rendered until all of its parameter values are valid.

Answer 1

[MathWorks Support Team]

The ability to automatically reset the "Value" property to "1" when repopulating a listbox is not available in MATLAB.

To work around this issue, set the active item in the list box to the first item before repopulating the listbox:

set(hListBox,'Value',1);

The following code provides an example where this workaround is used:

function [] = ChangeList()

% Example to demonstrate changing the items in a list

% Create two different lenght lists

list1 = {'Option 1', 'Option 2'};

list2 = {'Only Option'};

% Create a list box with the first list, set to second time.

hListBox = uicontrol('Style','listbox',...

                       'String',list1,...

                       'Position',[20 20 100 200],...

                       'Value',2);

% Create a button to set to list 1

hList1Button = uicontrol('Style','pushbutton',...

                           'String','List 1',...

                           'Position',[130,100,100,30],...

                           'Callback',@(eventObject,eventData)ChangeList(eventObject,eventData,hListBox,list1),...

                           'Tag','btn1');

% Create a button to set to list 2

hList2Button = uicontrol('Style','pushbutton',...

                           'String','List 2',...

                           'Position',[130,30,100,30],...

                           'Callback',@(eventObject,eventData)ChangeList(eventObject,eventData,hListBox,list2),...

                           'Tag','btn1');

end

% Create the callback

function [] = ChangeList(hObject,eventData,hListBox,list)

      set(hListBox,'Value',1); % Add this line so that the list can be changed

      set(hListBox,'String',list);

end