Setting popup menu strings from excel

I am reading the excel spreadsheet as follows:

function upload_Callback(hObject, eventdata, handles)
% hObject    handle to upload (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
guidata(hObject, handles);
[FileName1,PathName1] = uigetfile({'*.xls';'*.txt';'*.csv';'*.*'},'Select the text file that contains the data');
if isempty(FileName1)
    errordlg('No file was selected that contains the data so the calculation was aborted.');
    flag = true;
    return
end

S3.selected_dir_upload =fullfile(PathName1,FileName1);
handles.S3.selected_dir_upload =S3.selected_dir_upload  ;
[S3.num, S3.txt]=xlsread(S3.selected_dir_upload)
set(handles.upload_file, 'String', S3.selected_dir_upload)

set(handles.upload, 'UserData', S3);

After that I have a popup menu which should populate the texts from the excel sheet. For which I am trying this:

function popupmenu1_Callback(hObject, eventdata, handles)
% hObject    handle to popupmenu1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hints: contents = cellstr(get(hObject,'String')) returns popupmenu1 contents as cell array
%        contents{get(hObject,'Value')} returns selected item from popupmenu1
S3 = get(handles.upload, 'UserData');

set(handles.popupmenu1,'String',S3.txt);

But I am not able to get the list updated once the excel is read. Please suggest!

Answer 1

[ES]

I think you should update the popupmenu string from upload call back itself.

This will update the data on the poupmenu once the file is uploaded.