App Designer : Text field making visible and invisible when select and re-select same option from drop down menu

I am trying to make a text field visble when I select an option form the drop down and when I re-select that option, I want to make that text field hide. Please suggest me how to do this using drop dwon.

Answer 1

[Mario Malic]

You can create a property called

Last_Selection = '';

In the DropDownMenu callback

function DropDownValueChanged(app,event)
    if isempty(app.Last_Selection)
        app.Last_Selection = app.DropDownMenu.Value % Initialises Last_Selection on first callback
    else
        if isequal(app.Last_Selection, app.DropDownMenu.Value)
            % Hide something
            % I am not sure how it goes with hiding/removing dropdown values
            % First you have to assign to some other dropdown value and then remove it
            % if you don't want errors
            % ind = find (app.DropDownMenu.Value == app.DropDownMenu.Items); % get index of data to be removed
            % app.DropDownMenu.Value = change_to_other_value
            % app.DropDownMenu.Items{1,ind} = ''; % Test if it actually works
        else
            app.Last_Selection = app.DropDownMenu.Value
        end
        
    end

end

The question is, does the callback gets executed if the DropDownMenu.Value stays the same?

It might be more intuitive to the user what to do to remove the dropdown value, by adding the button instead.

[Saurabh Chaudhary]

Thankyou