(App Designer) set the dropdown with variable

I'm new to Matlab App Designer. I created a drop down buttom and want to set it with desired string variables.

I set like below picture but after run the app, the variables were not appeared in the drop down selections.

is there any mistake with my operation?

Thanks

Answer 1

[Prasanth Sunkara]

The reason for this behavior is that the values are set in the DropDownValueChanged instead of startupFcn.

If your intention is to initialize the values of the drop-down programmatically, you need to do that in ' startupFcn ' callback.

Alternatively, you can initialize the UI values directly from UI configuration parameters of the 'Design View'. However, I would personally recommend using the 'startupFcn' approach.

A quick tip: Why are you creating a new dropdown UI (check your 2 and 3 line numbers of your code) instead of updating the values?

Consider using the below approach.

        function startupFcn(app)
            value = app.DropDown.Value;
            app.DropDown.Items = {'Red','Blue'};
        end

Thanks, Prasanth