MATLAB Answers


How do I pass variables from one GUI to another

Asked by Gerrit
on 7 Nov 2013
Latest activity Edited by Wubie Engdew on 10 Aug 2019
I'm still struggling passing variables from one GUI to another by using handles.
I have created a GUI called "main" including a push button "OK" and an edit text box "a". Using "OK" will open a secong GUI "main2" which is supposed to return a variable "e".
function OK_Callback(hObject, eventdata, handles)
uiwait(main2); %Open main2
e = handles.e;
In "main2" I have a variable "e" being calculated in a function "calculate" which is being called after typing a number into the edit text box taged "d". By debugging I found out that "Calculate" returns the correct value. All cool so far.
function e = calculate(c,d)
e = c + d;
function d_Callback(hObject, eventdata, handles)
c = str2double(get(handles.c,'string'));
d = str2double(get(handles.d,'string'));
handles.e = e; % All cool until here!
guidata(hObject,handles); % Update handles structure
uiresume; % back to main
What I'm struggling with is: How do I get "e" (or its handle) from "main2" into "main"? Also set(handles.e,'string',e) is not working.
Anybody knows what's going on here?
Thank heaps for any help!

  1 Comment

Can you put some pictures with this app, please? Thank you!

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2 Answers

Answer by Jonathan LeSage on 7 Nov 2013
 Accepted Answer

You can use the setappdata and getappdata functions to pass values between UIs that you've developed. Since you're passing values between UIs, you want to store the values in the root so all other UIs can access them.
For example, after computing "e" in your main2 UI, you can store the value to the root:
By specifying a UI object handle of "0", we are telling MATLAB to store this value in the root directory. To access this value in your other UI, simple use the getappdata function:
e = getappdata(0,'evalue');
Hope this help to get you started!


thank you ! your answer is so helpful for me !
Could anyone tell me what are the possible values of the "UI object handle", please? and its respective description? I set it to "0" (as you said here) in my code and it didn't work. I don't know why. Thank you so much
write this code in UI one
and this code in another UI
getappdata(0,'write this code in another UI ',e);

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Answer by Image Analyst
on 30 Sep 2017


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