Check if GUI is open

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Pollok Tim
Pollok Tim on 21 Sep 2016
Answered: Kristoffer Walker on 21 Oct 2020
Hi everybody
I believe the answer to this question already exists several times online, but everything I tried failed.
I got in a GUI-figure the option to open an other GUI-figure. In the second GUI I got plots and the first one can update these plots. Therefore its interesting to know if the second GUI is already/still open when I activate the update.
I tried:
but I get the same result no matter if figure2 is open or not.
Is there an other way to get this information? I think of eventlisteners: figurehasbeenopened, figurehasbeenclosed
Thanks for help.

Accepted Answer

Adam on 21 Sep 2016
Edited: Adam on 21 Sep 2016
Keep hold of the handle of the figure when you launch it.
Then just do a
if ishghandle( otherFigureHandle )
if isgraphics( otherFigureHandle )
test when you want to see if it is open or not.
Adam on 21 Sep 2016
It depends where you are launching it from. I never use findobj myself (well, rarely) because I keep hold of all my handles if I need them in the future as e.g.
hFig = MyGUI(...)
to launch a GUI named MyGUI.
Then later on I can just use hFig. I can't tell from your question whether you mean you have a custom-made figure (e.g. from GUIDE) or whether you mean just a standard launched figure.
I would not recommend using
setappdata( 0,... )
generally, especially with common names like 'figure2', but if it works then ok. I don't use setappdata most of the time, but if I do I attach my data to a specific figure handle rather than the root object to keep it linked to the specific application.

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More Answers (4)

Benjamin Avants
Benjamin Avants on 17 Oct 2017
I know this question is old, but GUIDE created figures don't show up as results from findobj.
Instead, use
figure2handle = findall(0,'Tag','figure2');
if ~isempty(figure2handle)
% figure exists

Vahab Youssofzadeh
Vahab Youssofzadeh on 2 Jun 2017
Edited: Vahab Youssofzadeh on 2 Jun 2017
Here's another solution:
h = get(0, 'Children');
isempty(findobj(h,'name','NAME OF THE GUI'));
% isempty (findobj (h,'tag','NAME OF THE GUI'));

Nepenthes on 17 Jul 2018
This is a little late, but I chanced upon this solution when tackling a similar problem. H.isvalid or isvalid(H) should work. H can be a single handle, or a vector of handles. K>> H = figure; K>> G = plot(rand(5)); K>> delete(G(3:4)); K>> G.isvalid ans = 1 1 0 0 1 K>> H.isvalid ans = 1 K>> delete(H) K>> H.isvalid ans = 0

Kristoffer Walker
Kristoffer Walker on 21 Oct 2020
None of the above seems to work for me when I am trying to detect if a GUI created from AppDesigner is open. Does anyone know how to do this with AppDesigner GUI's?
Best regards,


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