Retrieving data from slider

t
t
2011 4 2
2 个回答
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0 个投票

I've been using GUIDE and I'm having trouble getting the value from the slider.
In the generated function
function slider1_Callback(hObject, eventdata, handles)
I can get the value with
sliderValue = get(handles.slider1,'Value')
But if I try using that in a user defined function I get this error:
??? Undefined variable "handles" or
class "handles.slider1".
Did I miss something?

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 采纳的回答

Matt Fig
Matt Fig 2011-4-2

0 个投票

In your user defined function doesn't accept the same three arguments, you will get this error. .
.
.
EDIT
Open the GUI with GUIDE. Double click on the slider to open the property editor. In the callback field, put this:
fun(gcbo,[],guidata(gcbo))
Where fun is the name of your function. fun will have to take three arguments just like shown:
function fun(hObject, eventdata, handles)

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t
t 2011-4-2
Do you mean like this?
function fun(hObject, eventdata, handles)
sliderValue = get(handles.slider1,'Value')
This gives me
??? Input argument "handles" is
undefined.
Matt Fig
Matt Fig 2011-4-2
How are you assigning this callback to the slider?

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更多回答（1 个）

t
t 2011-4-2

0 个投票

Like I posted in the comment above, I tried putting the same arguments in the function parameters
function fun(hObject, eventdata, handles)
sliderValue = get(handles.slider1,'Value')
and I get
??? Input argument "handles" is
undefined.

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Matt Fig
Matt Fig 2011-4-2
But how are you telling the GUI to call your function fun? And where is fun, in the GUI M-file, or outside?
t
t 2011-4-2
I've tried using fun() in the slider itself and on a button press just to test it.
fun() is in the GUI .m file, I'm doing everything in the same GUIDE generated .m file.
Matt Fig
Matt Fig 2011-4-2
See my above answer...
t
t 2011-4-2
I guess that works but it's really not an appropriate solution. The data needs to be accessed by several functions, all called using the GUI at different times.
I will have to use global variable as I've been wasting a lot of time trying to work out how data is stored and retrieved, which I have to say is rather unintuitive and difficult to do (for such a simple process).
Thanks a lot for helping.

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