GUI made without GUIDE not updating

I'm trying to make a GUI that pops up as soon as the main function starts and it contains a checkbox that can be used to stop the program when it is in a loop:

function mainFcn

h.fig = figure('Position', [100 100 100 100]);

h.cancelBox = uicontrol('Style', 'checkbox',...
                        'String', 'Cancel?',...
                        'Position', [10 10 10 10]);

set(h.cancelBox, 'callback', {@cancelBox, h});

drawnow;

i = 1;

while i == 1

     value = get(h.cancelBox, 'Value');

     if value == 1

        i = 0;
     else

        i = 1;

     end

end

function cancelBox(hObject, eventdata, handles)

set(hObject, 'Value', 1);

guidata(hObject, handles);

When I use disp(value); to see the value I am getting for the current value of the checkbox. It always says that the checkbox has a value of 0.

Answer 1

[Walter Roberson]

i == 0 is not an assignment statement.

Also your while loop is not giving an opportunity for any graphics interruptions. Graphics interruptions are only processed when there is a pause(), drawnow(), uiwait() or waitfor(), figure(), or the routine reaches the command prompt.

[qward]

The i == 0; was an typo I'm sorry about that. But I tried using drawnow() and it worked perfectly thank you.