App Designer ListBox and DropDown selection number

Hi All

I'm a GUIDE user but am now doing my first major GUI with App Designer (in 2017b), due to a nudge from Mathworks.

In GUIDE, the current selection number of a ListBox is extracted by handles.ListBox.Value (and for a DropDown, it is handles.DropDown.Value). In App designer the 'Value' field has been changed to output the content string of the selected entry and not the number of that entry. I can't find any field giving me the number? (which seems a step backwards to me in the context of vectorized code being the way to go)

Currently, I am awkwardly finding the number with strcmp inside a for loop.

           for i = 1:length(app.DropDown.Items)
               if strcmp(app.DropDown.Items{i},app.DropDown.Value)
                   break
               end
           end
           SelectNum = i;

How do I obtain the number in a quick way?

Thanks in advance

Answer 1

[Ashutosh Prasad]

Hello

You can use the ItemsData property of the app.DropDown class to specify whether you want the app.DropDown.Value to be numeric or string.

If you want numeric values just change the above code fragment with the following code snippet

>> app.DropDown.ItemsData = 1:length(app.DropDown.Items) 
>> SelectNum = app.DropDown.Value;

Let me know if this works for you

[Jurgens Wolfaardt]

Thank-you. That solves it!

[Kristoffer Walker]

Excellent development option