GUI and dealing with functions

Hello, I am new to the GUI and I have a problem is that very basic. The question is regarding dropdown menu. When I select a value in dropdown menu lets say 3 and assign it to some variable lets say K. I want it to be used in other functions but other functions don't see it. I tried global variable but that doesn't work.

Can you help me. Thank you

Answer 1

[Image Analyst]

If you're using GUIDE, you'd do

global K;
K = get(handles.popmenu1, 'Value');

and then put global K; into every other function that needs to see K. Did you do that?

Or else you can just use that "get" line in every other function that needs K and forget about setting it to a global variable, as long as that function can see the handles structure, which all call backs can. If you need it in a function you wrote, a non-callback function, then you'd have to pass handles in via the argument list.

Alternatively, did any of the ideas in the FAQ work for you? http://matlab.wikia.com/wiki/FAQ#How_can_I_share_data_between_callback_functions_in_my_GUI.28s.29.3F

[Alex Dytso]

Thank you for your response. So what I do is define:

global K;

K=3;

and then inside the definition of my funtion I put K as an argument

function myfunction(K)

I feel like I'm making a very fundamental mistake.

[Image Analyst]

No. If it's global, you don't need to pass it via arg lists anymore. Just declare it global again inside any function that needs to "see" it.

function myfunction()

global K;

try

% Your code goes here

catch ME

errorMessage = sprintf('Error in myfunction().\nThe error reported by MATLAB is:\n\n%s', ME.message);

uiwait(msgbox(errorMessage));

end

Answer 2

[John]

you can either, as Image Analyst states, get(handles.dropdownmenu1,'Value') during each function or you can simply store it in the structure handles.

For example if the name of the dropdown menu is dropdownmenu1. then:

handles.value = get(handles.dropdownmenu1,'Value');

%Also add the following line at the end of the function

guidata(hObject,handles)

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

Now 'handles.value' should be accessible to every other function.