Adding a List box to my Matlab GUI program. I want the list box to be populated with image files that were previously saved in the current folder.

I want to add a Listbox to my exsisting Matlab code. I want this listbox on the second tab of my code where the graph is plotted. I want the listbox to be populated with .bmp saved plots in the current folder. I have little experience with MATLAB gui and I am having trouble even displaying the list box.

Here is my current code

 if true
 function PizanoGUI()
 x=linspace(-2,2,100);
 power=1;
 y=x.^power;
 ctrl_fh = figure; 

 hPwr = uicontrol('Style','edit','Parent',... 
                     ctrl_fh,...
                     'Position',[45 100 100 20],...
                     'String',num2str(power),...
                     'CallBack',@pwrHandler);

 hButton = uicontrol('Style','pushbutton','Parent',ctrl_fh,... 
                    'Position',[45 150 100 20],...
                    'String','Reset','Callback',@reset); 

 hButton = uicontrol('Style','pushbutton','Parent',ctrl_fh,... 
                    'Position',[45 50 100 20],...
                    'String','EXIT','Callback',@close_Callback); 

 htext=uicontrol('Style', 'text',... 
 'String', 'Welcome! Please Enter any value p to view the graph of y=x^p then press enter', ... 
 'Position',[35,250,500,90], ... 
 'FontSize',20);

 function close_Callback(hObject, eventdata, handles) 

 close all;
 end

 function reset(source,event,handles,varargin) 
    fprintf('resetting...\n');
    power=1;
    set(hPwr,'String',num2str(power));
    y=x.^power;
    close(gcf);
    compute_and_draw_plot();
 end

 function pwrHandler(source,event,handles,varargin) 
    power=str2num(get(hPwr,'string'));
    fprintf('Setting power to %s\n',get(hPwr,'string'));
    close(gcf);
    compute_and_draw_plot();
 end

 function compute_and_draw_plot()
    plot_fh = figure;
    y=x.^power;
    figure(plot_fh); plot(x,y)
    xlabel('X axis') 
    ylabel('Y axis') 
    str = sprintf('Plot of Y=X^%d',power);
    title(str);

    hButton = uicontrol('Style','pushbutton','Parent',plot_fh,... 
                    'Position',[80 395 100 20],...
                    'String','Previous','Callback',@pushbutton1_Callback);

 function pushbutton1_Callback(source, eventdata, handles)
    close(gcf);
    PizanoGUI();
 end

 filename = inputdlg('Save figure as...');

 extensions = {'fig','bmp'};

 for k = 1:length(extensions)

 saveas(gcf, filename{:}, extensions{k})

 set(gcf,'PaperPositionMode','auto')

 end
 end
 end

Answer 1

[Yucheng Ma]

It is my understanding that you would like to create a List Box and fill it with the names of the BMP files in the current directory.

You can use the following statement to create a List Box:

hListBox = uicontrol('Style', 'listbox', ...
                     'Parent', plot_fh, ...
                     'Position', [100, 100, 50, 50], ...
                     'String', listString, ...
                     'Callback', @ListBoxCallback);

Please note that the position of the List Box must be within the current figure window to be displayed.

The "listString" above is a cell array of strings, specifying the texts displayed in the List Box. You can get a list of the names of the BMP files in the current directory as follows:

function listString = getBMPFiles()
   bmpfiles = dir('*.bmp');
   listString = cell(1, numel(bmpfiles));
   [listString{:}] = bmpfiles.name;
end

You can refer to the following document for more information on "dir":

http://www.mathworks.com/help/matlab/ref/dir.html

In order to update the contents of the List Box after a figure is saved, you can get the new "listString" with the function above and use "set" to change the "String" property of the List Box:

set(hListBox, 'String', listString);

You can refer to the following documentation for a more detailed example of using the List Box in MATLAB UI: http://www.mathworks.com/help/matlab/creating_guis/interactive-list-box-in-a-guide-gui.html