If I change a property of a UIControl in a callback do I still need to call setappdata before exiting?

I start my call back with

handles = getappdata(gcf,'handles');

So I have created a local copy of the handles structure.

Then I modify a control with

set(handles.Batch,'value',1);

Since handles.batch is a handle, don't I automatically change its properties without having to call

setappdata(gcf,'handles',handles);

Answer 1

[Walter Roberson]

Correct, you only have to call setappdata() if you modify the structure itself.

Note: it is more common to use guidata() to manage a handles structure. It does the same thing as setappdata() of a property named UsedByGUIData_m, but people are more accustomed to reading guidata()

[Eugene Davis]

Thanks Walter. In my app, which I inherited, there are several GUI data structures. They chose not to add these other structures to the grand handles structure. I suppose all the logic, wrt guidata(), about how to deal with the handles structure apply to other structures. The main difference is that these other structures do not contain GUI handles.