How can i use a global var with call_back functions?

Question

Edward P 2011-11-3

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/20222-how-can-i-use-a-global-var-with-call_back-functions

The problem is: how can i declare a global var, so i can use it on all functions of my guidata?

for example:

function pushbutton5_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton5 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
---->  cpselect(E,D);
guidata(hObject, handles);
% --- Executes on button press in Inserir.
function pushbutton4_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton4 (see GCBO)
% Invoca duas fotos
echo ImRectOpen off;
----->  global E D;
[E,D]=ImRectOpen();
imshow(E,'Parent',handles.axes3);
imshow(D,'Parent',handles.axes4);
set(handles.pushbutton1,'enable','on');
set(handles.pushbutton5,'enable','on');
guidata(hObject, handles);

First, i've ran the pushbutton_callback4 and then pushbutton_callback5. On pushbutton_callback5 global variables (E and D) that were declared on pushbutton_callback4, cant be found.