How to prompt an error message box if no image is selected? (App Design)

I have an image processing project that I am currently working on. I would like to display a message box prompting an "error" if the user fails to select an image. As in:

The user selects load image, and if the user decides to exit out of the selection, an error message is shown. Thanks.

[Tommy]

file = 0;
while ~file
    [file, path] = uigetfile;
    if ~file
        waitfor(msgbox('Pick a file.'))
    end
end
disp([path file])

This will bring up a dialog box for selecting a file, and if the user clicks 'Cancel' it will display another box that says 'Pick a file.' Once they close that box, it will again prompt them to pick a file. Only after they pick a file will the code continue past the while loop. Is this similar to what you are looking for?

Answer 1

[Divya Yerraguntla]

Hi Cyrick,

You could use the below model code to achieve your purpose:

[file,path] = uigetfile; % Open file selection dialog box
if isequal(file,0)
   f = errordlg('Must pick a file'); % If cancel button is pressed Error pops up
end

Have a look at uigetfile and errordlg for more information about these functions.

Hope it helps!