Question
I call a data application from my main application and store the data app handle in a main app local variable.. The data app has a Close button which first sets the handle to [] (by using the callingApp handle and then deletes itself. This works fine, no problem. The probem occurs when the user closes the data app window using the "X" in the upper r/h corner. This action does execute the delete callback, but I'm unable to add code to this callback to also empty the data app handle. I'd prefer the user not use the "X", but it's impossible to prevent him from doing so inadvertently. Isvalid would do the trick, but it's not available in 2022b. I could upgrade to 2023a, but I'd prefer not doing so at this time. An solutions?
Expert Answer
Prashant Kumar
PhD Expert
Answered Nov 20, 2025
> I'd prefer the user not use the "X", but it's impossible to prevent him from doing so inadvertently.
You can set the [x] close button to be unresponsive to clicks.
uif = uifigure('CloseRequestFcn',[])
Or display an alert box to inform the user to use the app's close button
uif = uifigure('CloseRequestFcn',@(f,~)uialert(f,'Use the app''s close button','No-Can-Do'))
To close these figures
close(uif,'force') % or delete(uif)
or, if you lose the handle, this deletes all figures
close all force
100% Run Guarantee
3-Hour Fast-Track Delivery
Need a Custom Version or Complete Simulation for This Problem?
Our 500+ PhD engineers build, debug, and optimize working MATLAB scripts and Simulink (.slx) models tailored to your exact assignment rubrics with zero plagiarism.
Tested on MATLAB R2024b / R2026a
Turnitin 0% Plagiarism Report
Free 7-Day Revisions Guarantee
Have a different question? Ask here
Related MATLAB Questions & Solutions
Browse All →
Explore similar technical troubleshooting questions and verified MATLAB solutions:
Ready-to-Run MATLAB & Simulink Projects
Browse All Projects →