Getting value of selected string in Popup menu.

I am trying to make a GUI. Depending on the option selected in popup menu 3 the selected operation should be performed on images. However when i am trying to get the value from popupmenu3 I am getting the following error.

Error in matlab.graphics.internal.figfile.FigFile/read>@(hObject,eventdata)pr('popupmenu3_Callback',hObject,eventdata,guidata(hObject)).

Below is the code for this popupmenu.

function popupmenu3_Callback(hObject, eventdata, handles)

contents = get(hObject,'String');
a = contents{get(hObject,'Value')} ;

% --- Executes during object creation, after setting all properties.
function popupmenu3_CreateFcn(hObject, eventdata, handles)
% hObject    handle to popupmenu3 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    empty - handles not created until after all CreateFcns called

% Hint: popupmenu controls usually have a white background on Windows.
%       See ISPC and COMPUTER.
if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
    set(hObject,'BackgroundColor','white');
end

When I make a simple GUI with only popupmenus I don't get the error. But when I try to get the value of selected string I am getting error.

[Image Analyst]

Attach your m and fig files.

[Sidra Aleem]

Below are attached both of files @Image Analyst. Along with this two, ReadFileNames is also attached. It is the function that is being used.

[per isakson]

• You should always show the entire error message.
• See Debug a MATLAB Program
• This folder name looks strange to me

127         cd(handles.Dir.Functions_Dir)
K>> handles.Dir.Functions_Dir
ans =
D:\ÎÒµÄÎĵµ\MATLAB\Image Processing\Functions\
K>>

[Sidra Aleem]

@per isakson I saw the entire message. This name is strange to you because my desktop has Chinese as a language. That's why its appearing strange in your system. I have figured out my issue. I was misplacing some of my folder names.

Answer 1

[Walter Roberson]

Your code does not protect against the possibility that there are no subdirectories in the selected directory. There are no prompts as to what the purpose of the selecting a directory is, so you should assume that users might select something with no subdirectories.

Your code should use fullfile() instead of splicing strings together in the line

handles.People(i).Images = ReadFileNames([handles.Dir.Home_Dir '\Inputs\' dirinfo(i,1).name]);

In Browse_Callback you do

foldername = uigetdir('D:\ÎÒµÄÎĵµ\MATLAB\Image Processing','Select folfer');
handles.fname=foldername;

which is fine in itself, and in pushbutton2_Callback you use handles.fname to refer to the selected directory and you find the sub-directories of that. But then just a few lines further down you use

        cd(handles.Dir.Functions_Dir)

which assumes that handles.Dir.Functions_Dir is the same as handles.fname . Why bother to have two different variables for the same purpose? Why bother to ask the user what directory to use if you are always going to assume that handles.Dir.Functions_Dir refers to the same place? Or flip that around: if you bothered to ask the user what folder to use (perhaps because they are using a different machine where the folders are in a different location) then why are you are ignoring the user-selected folder name?

You do not need to do the cd() at all. You can use

   handles.People(i).Images = ReadFileNames( fullfile(Input_Dir, dirinfo(i,1).name) );

By the way, in ReadFilenames, you should be using fullfile() instead of worrying about NameSeperator . Also, although it is not well known, internally MS Windows uses '/' as its directory separator, using '\' for public presentation. Because the real directory separator is '/' you can just always use '/' if you are going to code directory separators yourself -- but don't do that, use fullfile() instead.

[Sidra Aleem]

@Walter Roberson "handles.fname" has the path of "Input folder". handles.Dir.Functions_Dir has the path of the folder that is having the "function files". I will make use of fullfile() as you suggested. In the input folder, now there are 40 sub directories. I am having the issue that when i run the code for the first time it lets me select any of the option in popupmenu3. However after that, if i try to select any other option from poupmenu3 following error occurs.

Undefined function or variable 'cvv'.

Error in matlab.graphics.internal.figfile.FigFile/read>@(hObject,eventdata)cvv('popupmenu3_Callback',hObject,eventdata,guidata(hObject))

Error while evaluating UIControl Callback

The same error comes if i click "Refresh" button on my GUI. Below are attached my fig file and .m file. Kindly help me to solve this problem.

[Walter Roberson]

Your code has cd(), so you are no longer in the directory that has the cvv.m file in it.

[Sidra Aleem]

@Walter Roberson my code has cd.. as well. That is bringing me back to the folder that has cvv.m file.

[Walter Roberson]

You

cd(handles.Dir.Functions_Dir)

and later

cd ..

Are we certain that cvv.m is one directory level above Functions_Dir ? Let us look:

    handles.Dir.Home_Dir        = [handles.Dir.Present_Dir 'cvv\'];                   % Home Directory
    handles.Dir.Functions_Dir   = [ handles.Dir.Home_Dir 'Functions\' ];                            %Functions Directory

One level above Functions_Dir is going to be Home_Dir, which is a directory named cvv . It is unlikely in MS Windows that you would be using both a directory named cvv and a file named cvv.m in the same directory..

[Sidra Aleem]

@Walter Roberson with your help i figured out that after imwrite() the control went to Output folder. From there I was not moving the control to home directory.

    cd(imagepath)
            imwrite(images,[ Name ' -FFT_Result.jpg'], 'jpg');

So after this line I did

   cd( (handles.Dir.Home_Dir)

And now its working fine. And Thanks for pointing out that .m file and directory files names are same I will change that as well. Thanks for your help.