GUI: Can't access data from another callback function with handles

I'm using GUIDE, and I've imported data like this:

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

% Hint: get(hObject,'Value') returns toggle state of control_browse_button
[control_file control_pathname] = uigetfile({'*.xlsx'}, 'File Selector');
set(handles.control_filename,'String', control_file);
[control_data control_labels] = xlsread(control_file);
handles.control_data = control_data;
handles.control_labels = control_labels;

And then I attempted to access control_labels:

function loadfile_button_Callback(hObject, eventdata, handles)
% hObject    handle to loadfile_button (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
% Hint: get(hObject,'Value') returns toggle state of loadfile_button
for i = 3:size(handles.control_labels,1)
ctrl_labels{i-2} = handles.control_labels{i,1};
end

....
%(rest of the code for this callback)
...

But I'm getting the error:

Reference to non-existent field 'control_labels'

Am I not using handles properly? How should I access control_labels from another callback function?

Thanks!

[Rik]

It's also a good idea to initialize the field when starting the GUI, and trigger an error if the user clicks the load button before the control browse button.

@G A: please move your answer to the answer section.

Answer 1

[G A]

G A on 31 Aug 2019 at 8:38

Put the line

guidata(hObject, handles);

at the end of your function control_browse_button_Callback.

Have a look here:

doc guidata

[Peter Smith]

Awesome, thanks for the help