displaying contents in a list bx after button press

Hi I have a GUI, in which i press a button and it obtains all he file names from my database. I then want this to be displayed within a list box but can't get the list box to update can someone help please?

here is my code so far:

% --- Executes on button press in pushbutton7.
function pushbutton7_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton7 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

global str;

str = getfilenames;

disp(str);

% --- Executes during object creation, after setting all properties.
function listbox1_CreateFcn(hObject, eventdata, handles)
% hObject    handle to listbox1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    empty - handles not created until after all CreateFcns called

% Hint: listbox controls usually have a white background on Windows.
%       See ISPC and COMPUTER.
if ispc && isequal(get(hObject,'BackgroundColor'), 
get(0,'defaultUicontrolBackgroundColor'))

set(hObject,'BackgroundColor','white');
end

 global str;

 set(hObject, 'String', str2 );

Answer 1

[Azzi Abdelmalek]

Your code is not clear for me, but I see that you are creating a list in the listbox callback while you should do it in the push button callback

[Gurvinder]

Sorry here you go

function pushbutton7_Callback(hObject, eventdata, handles) global str;

str = getfilenames;

disp(str);

the above push button in my gui is calling another function i made to obtain all the file names.

I want it to update my listbox below once i click the button but don't know how...code for list box below:

function listbox1_CreateFcn(hObject, eventdata, handles) global str;

 set(hObject, 'String', str2 );

could you provide an example of what you mean or know of any documentation that i could read to help?

[Azzi Abdelmalek]

Use

function pushbutton7_Callback(hObject, eventdata, handles)  
str = getfilenames;
set(handles.listbox1, 'String', str );