nested function / Pass Data between 2 functions

So this is my exampple Code. Now, i want to know: how can i pass the variable "Number" from the 1st function into the 2nd one. (hope pass is the right word)

function Example_Callback(hObject, eventdata, handles)
         Number = get(handles.edit1,'String')
         Data = findobj('type','axes')
                  set(Data,'buttondownfcn',@ClickToDrag)

                        function ClickToDrag (gcbo,evendata,handles) 
                                 disp('Number')

Answer 1

[Max Müller]

1 Comment Adam on 13 Aug 2014 at 12:07

>>> I always forget exactly what are the fixed arguments you have to have for a callback function, but I'm pretty sure your Click function shouldn't take 'handles' as an argument. If it takes an argument representing 'A' (which may well end up in handles the way you have it) then that should be simply usable in your callback.

e.g.

function Click( gcbo, eventdata, A )

Answer 2

[Adam]

set(Data,'buttondownfcn',{@ClickToDrag,Number})

should do the job.

Incidentally, is 'handles' appearing in your ClickToDrag function because you aren't passing it to the function. I would also never advise passing handles to a callback function. Instead pass the handle of your main figure and get the handles from that within your callback. That will give you the handles structure at the time of the callback. If you pass handles to a callback you will get the version of handles at the time it was passed.

[Max Müller]

and this doesn't work either.....

Answer 3

[Joakim Magnusson]

You could store it in handles like this in the first function:

handles.number = Number;

Then you could use it in your second function like this:

 disp(handles.number);

[Joakim Magnusson]

Did you solve it?

[Max Müller]

that doesnt quite work.

Answer 4

[Max Müller]

I am forced to use v2006a

I have a solution using getappdata|setappdata.

function pushbutton2_Callback(hObject, eventdata, handles)
        A = 5
        Data = findobj('type','axes');
        set(Data(1),'buttondownfcn',{@Click,A});
        setappdata(Data(1), 'my_A', A);

      function Click (gcbo,evendata,handles)
          disp('Click')
          Data = findobj('type','axes');
          A = getappdata(gcbo, 'my_A');
          disp(['A = ' A])

[Adam]

I always forget exactly what are the fixed arguments you have to have for a callback function, but I'm pretty sure your Click function shouldn't take 'handles' as an argument. If it takes an argument representing 'A' (which may well end up in handles the way you have it) then that should be simply usable in your callback.

e.g.

function Click( gcbo, eventdata, A )

Answer 5

[Max Müller]

Sorry for being such an idiot. My Job isnt easy .... Today i try to work on my knowledge about handles. But guys, is there anyway my CallbackFunction can return Data to my parentFunction ? my Supervisor said no. What do u say ?

[Adam]

A callback does not have a parent function, but you can attach data in your callback to the handles structure that can be accessed from any other callback.

handles = guidata( gcbo );

handles.myData = someData;

guidata( gcbo, handles );

if you have gcbo or the main figure handle in a standard callback that comes from a pushbutton or similar. I tend to pass the main figure handle to my created callbacks so I can access the handles structure from that.

Make sure not to forget that last line though. I still forget it from time to time after 8 years using it and if you don't then your handles will not get updated to the gui.

[Max Müller]

thanks a lot. I am trying to learn more about matlab handles right now. Hope can become a better matlab programmer.