Using Matlab App Designer with 2 Dependent Pop Up Menus

I am trying use app designer to write the following program.

Part 1: There's a first drop down menu with 2 options: California, Texas

Part 2: There a second drop down menu that depends on the first drop down menu. If California is selected, the second drop down menu has the following options: San Diego, Sacramento, Irvine. If Texas is selected, the drop down menu has the following options: Austin, Dallas, Houston

How do I write a program that successfully connects the second drop down menu to the first drop down menu?

Answer 1

[StefBu]

You can do this by using a callback on changinge the value in your first drop down. All the magic is done in

function DropDown1ValueChanged(app, event)

Here you go:

classdef app1 < matlab.apps.AppBase

    % Properties that correspond to app components
    properties (Access = public)
        UIFigure          matlab.ui.Figure
        DropDown2_2Label  matlab.ui.control.Label
        DropDown2_2       matlab.ui.control.DropDown
        DropDown1Label    matlab.ui.control.Label
        DropDown1         matlab.ui.control.DropDown
    end

    methods (Access = private)

        % Value changed function: DropDown1
        function DropDown1ValueChanged(app, event)
            value = app.DropDown1.Value;
            switch value
                case "California"
                    app.DropDown2_2.Items = {'San Diego', 'Sacaramento', 'Irvine'};
                case "Texas"
                    app.DropDown2_2.Items = {'Austin', 'Dallas', 'Houston'};
            end
                    
        end
    end

    % App initialization and construction
    methods (Access = private)

        % Create UIFigure and components
        function createComponents(app)

            % Create UIFigure
            app.UIFigure = uifigure;
            app.UIFigure.Position = [100 100 640 480];
            app.UIFigure.Name = 'UI Figure';

            % Create DropDown2_2Label
            app.DropDown2_2Label = uilabel(app.UIFigure);
            app.DropDown2_2Label.HorizontalAlignment = 'right';
            app.DropDown2_2Label.Position = [370 287 69 22];
            app.DropDown2_2Label.Text = 'DropDown2';

            % Create DropDown2_2
            app.DropDown2_2 = uidropdown(app.UIFigure);
            app.DropDown2_2.Items = {'San Diego', 'Sacaramento', 'Irvine'};
            app.DropDown2_2.Position = [454 287 100 22];
            app.DropDown2_2.Value = 'San Diego';

            % Create DropDown1Label
            app.DropDown1Label = uilabel(app.UIFigure);
            app.DropDown1Label.HorizontalAlignment = 'right';
            app.DropDown1Label.Position = [97 287 69 22];
            app.DropDown1Label.Text = 'DropDown1';

            % Create DropDown1
            app.DropDown1 = uidropdown(app.UIFigure);
            app.DropDown1.Items = {'California', 'Texas'};
            app.DropDown1.ValueChangedFcn = createCallbackFcn(app, @DropDown1ValueChanged, true);
            app.DropDown1.Position = [181 287 100 22];
            app.DropDown1.Value = 'California';
        end
    end

    methods (Access = public)

        % Construct app
        function app = app1

            % Create and configure components
            createComponents(app)

            % Register the app with App Designer
            registerApp(app, app.UIFigure)

            if nargout == 0
                clear app
            end
        end

        % Code that executes before app deletion
        function delete(app)

            % Delete UIFigure when app is deleted
            delete(app.UIFigure)
        end
    end
end

Greetins Stefan

[Wesley]

Perfect, Thank You!!