Remove UI Control edit box referenced with handles

Hi,

I have created an UI control edit boxes and are created and stored in handles for eg

for i=1:20

handles.sensname(i) = uicontrol('style', 'edit','Position',  [95, b-(i-1)*20, 180, 17],'BackgroundColor',[1 1 1]);

end

Now after creating this, i want to delete the ui control editboxes. What i tried is

        for i=1:20
            delete(handles.sensname(i));
        end

But I am getting the error 'Root object may not be deleted'. i know it may be that handle values cannot be deleted, then how to solve my problem?

Appreciate any idea to solve this

Karthik

Answer 1

[Walter Roberson]

Is it possible that your code is not quite as shown, and that you initialize handles.sensname as an array with more elements than you store handles for? If so then the extra entries would be 0 and you would get the error you get.

Suggested replacement code (no loop needed)

delete( handles.sensname(handles.sensname > 0) );

[Karthik KJ]

no that also not woking.

I have added the code below, which comes under a pushbutton,

if str2num(get(handles.nosensorentry_tag,'string'))<26

for i=1:str2num(get(handles.nosensorentry_tag,'string'))

handles.sensname(i) = uicontrol('style', 'edit','Position', [95, b-(i-1)*20, 180, 17],'BackgroundColor',[1 1 1]);

handles.sensnot(i) = uicontrol('style', 'edit','Position', [410, b-(i-1)*20, 45, 17],'BackgroundColor',[1 1 1]);

handles.sensvtsno(i) = uicontrol('style', 'edit','Position', [535, b-(i-1)*20, 40, 17],'BackgroundColor',[1 1 1],'string',i);

handles.sensmeasno(i) = uicontrol('style', 'edit','Position', [650, b-(i-1)*20, 40, 17],'BackgroundColor',[1 1 1]);

end

handles.count=str2num(get(handles.nosensorentry_tag,'string'));

guidata(hObject, handles);

else

for i=1:handles.count

delete(handles.sensname(handles.sensname > 0) );

end

for i=1:str2num(get(handles.nosensorentry_tag,'string'))

if i<26

handles.sensname(i) = uicontrol('style', 'edit','Position', [5, b-(i-1)*20, 180, 17],'BackgroundColor',[0.941 0.922 0.557]);

handles.sensnot(i) = uicontrol('style', 'edit','Position', [385, b-(i-1)*20, 45, 17],'BackgroundColor',[0.941 0.922 0.557]);

handles.sensvtsno(i) = uicontrol('style', 'edit','Position', [510, b-(i-1)*20, 40, 17],'BackgroundColor',[0.941 0.922 0.557],'string',i);

handles.sensmeasno(i) = uicontrol('style', 'edit','Position', [625, b-(i-1)*20, 40, 17],'BackgroundColor',[0.941 0.922 0.557]);

guidata(hObject, handles)

else

handles.sensname(i) = uicontrol('style', 'edit','Position', [188, b-(i-26)*20, 180, 17],'BackgroundColor',[0.886 0.855 0.612]);

handles.sensnot(i) = uicontrol('style', 'edit','Position', [435, b-(i-26)*20, 45, 17],'BackgroundColor',[0.886 0.855 0.612]);

handles.sensvtsno(i) = uicontrol('style', 'edit','Position', [555, b-(i-26)*20, 40, 17],'BackgroundColor',[0.886 0.855 0.612],'string',i);

handles.sensmeasno(i) = uicontrol('style', 'edit','Position', [675, b-(i-26)*20, 40, 17],'BackgroundColor',[0.886 0.855 0.612]);

guidata(hObject, handles)

end

end

end

[Jan]

Please, Karthik, stop writing "does not work" without explaining what happens: if there is an error message, post a complete copy. If the results differ from your expectations, explain what you want and what you get with all necessary details.

[Walter Roberson]

I said "(no loop needed)". Change

for i=1:handles.count

delete(handles.sensname(handles.sensname > 0) );

end

to

delete(handles.sensname(handles.sensname > 0) );

handles.sensname(:) = 0; %clear them afterwards so old value is not hanging around next time you execute

[Karthik KJ]

Hi Walter,

You are correct, i was initialising with higher number of entries , now i corrected it . Now this code is working. Thanks alot Walter,Sean,Jan

for i=1:20

delete(handles.sensname(i));

end

[Walter Roberson]

More efficient would be

delete(handles.sensname(1:20));

with no loop (just the one line.)

Answer 2

[Sean de Wolski]

That means that handles.sensname(i) is returning a 0, the handle to the root object.

It it kind of hard to tell you what is broken with it, but perhaps you could just check for zeros first.

for ii = 1:10;
 if logical(handles.sensname(ii))
   delete(handles.sensname(ii));
 end
end

More Note also that if I run those two lines of code back2back I don't get the error:

figure;
for i=1:20
  handles.sensname(i) = uicontrol('style', 'edit','Position',  [95, pi-(i-1)*20, 180, 17],'BackgroundColor',[1 1 1]);
end
for i=1:20
  delete(handles.sensname(i));
end

[Karthik KJ]

it doesnt work. I used this example

figure

u=uicontrol('style','text');

delete(u).

Since i am referencing in handles, it is showing the error.

[Jan]

Or: if handles.sensname(ii) ~= 0

[Jan]

@Karthik: What did not work and which error message do you get?

The problem is *not* related to the fact, that the handle of the UICONTROL is stored in a struct called "handles". Therefore I do not understand, what "referencing in handles" means and how it could affect the error.

[Karthik KJ]

I am not quite sure about my understanding towards handles, as i shown the example delete(u) will delete the edit box got created. But if I am deleting the edit boxes created using the gui handles, i could not able to delete the created edit boxes.

Referencing in handles, i thought handle of the uicontrol cant be deleted.

[Walter Roberson]

Any handle graphics object can be deleted _except_ for the root object (0). This includes uicontrol() and text() and plots and surf() and so on.