MATLAB Creating Graphical User Interfaces

If your code does not have direct access to a component, use the findobj function to

search for that component. If the search is successful, findobj returns the component as

output. Then you can access the component’s properties.

The following app code uses the UserData property to share information about the slider.

To see how it works, copy and paste this code into an editor and run it.

function my_slider()

hfig = figure();

slider = uicontrol('Parent', hfig,'Style','slider',...

'Units','normalized',...

'Position',[0.3 0.5 0.4 0.1],...

'Tag','slider1',...

'UserData',struct('val',0,'diffMax',1),...

'Callback',@slider_callback);

button = uicontrol('Parent', hfig,'Style','pushbutton',...

'Units','normalized',...

'Position',[0.4 0.3 0.2 0.1],...

'String','Display Difference',...

'Callback',@button_callback);

end

function slider_callback(hObject,eventdata)

sval = hObject.Value;

diffMax = hObject.Max - sval;

data = struct('val',sval,'diffMax',diffMax);

hObject.UserData = data;

% For R2014a and earlier:

% sval = get(hObject,'Value');

% maxval = get(hObject,'Max');

% diffMax = maxval - sval;

% data = struct('val',sval,'diffMax',diffMax);

% set(hObject,'UserData',data);

end

function button_callback(hObject,eventdata)

h = findobj('Tag','slider1');

data = h.UserData;

% For R2014a and earlier:

% data = get(h,'UserData');

display([data.val data.diffMax]);

end

11 Manage Application-Defined Data