如何用matlab app designer设计一个计算器

设计一个简单的计算器需要以下步骤：

1. 打开 Matlab 中的 App Designer 工具，创建一个新的 App。

2. 在 App Designer 界面中添加两个 UI 组件：一个用于显示计算结果的文本框（Text），一个用于输入计算表达式的编辑框（Edit Field）。

3. 添加数字按钮和运算符按钮。可以使用按钮组件（Button Group）来组织各种按钮。为了使计算器更加美观，可以使用 MATLAB 的内置图标库，如“plus”，“minus”，“times”和“divide”等。

4. 为每个按钮添加回调函数。这些回调函数将在用户单击按钮时执行。例如，单击数字按钮时，将数字添加到编辑框中；单击运算符按钮时，将运算符添加到编辑框中。

5. 为“=”按钮添加回调函数。该函数将使用 eval 函数计算编辑框中的表达式，并将结果显示在文本框中。

6. 测试计算器应用程序。运行应用程序并测试各种功能，例如输入数字、运算符和计算表达式。

下面是一个简单的示例代码：

classdef CalculatorApp < matlab.apps.AppBase

    % Properties that correspond to app components
    properties (Access = public)
        UIFigure     matlab.ui.Figure
        ResultText   matlab.ui.control.Label
        ExpressionEditField  matlab.ui.control.EditField
        ButtonGroup  matlab.ui.container.ButtonGroup
        NumButton1   matlab.ui.control.Button
        NumButton2   matlab.ui.control.Button
        NumButton3   matlab.ui.control.Button
        NumButton4   matlab.ui.control.Button
        NumButton5   matlab.ui.control.Button
        NumButton6   matlab.ui.control.Button
        NumButton7   matlab.ui.control.Button
        NumButton8   matlab.ui.control.Button
        NumButton9   matlab.ui.control.Button
        NumButton0   matlab.ui.control.Button
        PlusButton   matlab.ui.control.Button
        MinusButton  matlab.ui.control.Button
        TimesButton  matlab.ui.control.Button
        DivideButton matlab.ui.control.Button
        EqualsButton matlab.ui.control.Button
    end

    % Callbacks that handle component events
    methods (Access = private)

        % Button pushed function: NumButton1
        function NumButton1Pushed(app, event)
            appendText(app, '1');
        end

        % Button pushed function: NumButton2
        function NumButton2Pushed(app, event)
            appendText(app, '2');
        end

        % Button pushed function: NumButton3
        function NumButton3Pushed(app, event)
            appendText(app, '3');
        end

        % Button pushed function: NumButton4
        function NumButton4Pushed(app, event)
            appendText(app, '4');
        end

        % Button pushed function: NumButton5
        function NumButton5Pushed(app, event)
            appendText(app, '5');
        end

        % Button pushed function: NumButton6
        function NumButton6Pushed(app, event)
            appendText(app, '6');
        end

        % Button pushed function: NumButton7
        function NumButton7Pushed(app, event)
            appendText(app, '7');
        end

        % Button pushed function: NumButton8
        function NumButton8Pushed(app, event)
            appendText(app, '8');
        end

        % Button pushed function: NumButton9
        function NumButton9Pushed(app, event)
            appendText(app, '9');
        end

        % Button pushed function: NumButton0
        function NumButton0Pushed(app, event)
            appendText(app, '0');
        end

        % Button pushed function: PlusButton
        function PlusButtonPushed(app, event)
            appendText(app, '+');
        end

        % Button pushed function: MinusButton
        function MinusButtonPushed(app, event)
            appendText(app, '-');
        end

        % Button pushed function: TimesButton
        function TimesButtonPushed(app, event)
            appendText(app, '*');
        end

        % Button pushed function: DivideButton
        function DivideButtonPushed(app, event)
            appendText(app, '/');
        end

        % Button pushed function: EqualsButton
        function EqualsButtonPushed(app, event)
            expression = app.ExpressionEditField.Value;
            result = eval(expression);
            app.ResultText.Text = num2str(result);
        end
    end

    % App initialization and construction
    methods (Access = private)

        % Code that executes after component creation
        function startupFcn(app)
            % Initialize the result text
            app.ResultText.Text = '0';
        end

        % Append text to the expression edit field
        function appendText(app, text)
            currentValue = app.ExpressionEditField.Value;
            app.ExpressionEditField.Value = strcat(currentValue, text);
        end
    end

    % Component initialization
    methods (Access = private)

        % Create UIFigure and components
        function createComponents(app)

            % Create UIFigure and hide until all components are created
            app.UIFigure = uifigure('Visible', 'off');
            app.UIFigure.Position = [100 100 640 480];
            app.UIFigure.Name = 'Calculator';

            % Create ResultText
            app.ResultText = uilabel(app.UIFigure);
            app.ResultText.HorizontalAlignment = 'right';
            app.ResultText.FontSize = 20;
            app.ResultText.FontWeight = 'bold';
            app.ResultText.Position = [51 386 532 37];
            app.ResultText.Text = '0';

            % Create ExpressionEditField
            app.ExpressionEditField = uieditfield(app.UIFigure, 'text');
            app.ExpressionEditField.HorizontalAlignment = 'right';
            app.ExpressionEditField.FontSize = 20;
            app.ExpressionEditField.FontWeight = 'bold';
            app.ExpressionEditField.Position = [51 340 532 37];

            % Create ButtonGroup
            app.ButtonGroup = uibuttongroup(app.UIFigure);
            app.ButtonGroup.SelectionChangedFcn = createCallbackFcn(app, @ButtonGroupSelectionChanged, true);
            app.ButtonGroup.TitlePosition = 'centertop';
            app.ButtonGroup.FontSize = 20;
            app.ButtonGroup.FontWeight = 'bold';
            app.ButtonGroup.Position = [51 77 532 251];
            app.ButtonGroup.BorderType = 'none';

            % Create NumButton1
            app.NumButton1 = uibutton(app.ButtonGroup, 'push');
            app.NumButton1.FontSize = 20;
            app.NumButton1.FontWeight = 'bold';
            app.NumButton1.Position = [17 186 80 80];
            app.NumButton1.Text = '1';
            app.NumButton1.ButtonPushedFcn = createCallbackFcn(app, @NumButton1Pushed, true);

            % Create NumButton2
            app.NumButton2 = uibutton(app.ButtonGroup, 'push');
            app.NumButton2.FontSize = 20;
            app.NumButton2.FontWeight = 'bold';
            app.NumButton2.Position = [117 186 80 80];
            app.NumButton2.Text = '2';
            app.NumButton2.ButtonPushedFcn = createCallbackFcn(app, @NumButton2Pushed, true);

            % Create NumButton3
            app.NumButton3 = uibutton(app.ButtonGroup, 'push');
            app.NumButton3.FontSize = 20;
            app.NumButton3.FontWeight = 'bold';
            app.NumButton3.Position = [217 186 80 80];
            app.NumButton3.Text = '3';
            app.NumButton3.ButtonPushedFcn = createCallbackFcn(app, @NumButton3Pushed, true);

            % Create NumButton4
            app.NumButton4 = uibutton(app.ButtonGroup, 'push');
            app.NumButton4.FontSize = 20;
            app.NumButton4.FontWeight = 'bold';
            app.NumButton4.Position = [17 96 80 80];
            app.NumButton4.Text = '4';
            app.NumButton4.ButtonPushedFcn = createCallbackFcn(app, @NumButton4Pushed, true);

            % Create NumButton5
            app.NumButton5 = uibutton(app.ButtonGroup, 'push');
            app.NumButton5.FontSize = 20;
            app.NumButton5.FontWeight = 'bold';
            app.NumButton5.Position = [117 96 80 80];
            app.NumButton5.Text = '5';
            app.NumButton5.ButtonPushedFcn = createCallbackFcn(app, @NumButton5Pushed, true);

            % Create NumButton6
            app.NumButton6 = uibutton(app.ButtonGroup, 'push');
            app.NumButton6.FontSize = 20;
            app.NumButton6.FontWeight = 'bold';
            app.NumButton6.Position = [217 96 80 80];
            app.NumButton6.Text = '6';
            app.NumButton6.ButtonPushedFcn = createCallbackFcn(app, @NumButton6Pushed, true);

            % Create NumButton7
            app.NumButton7 = uibutton(app.ButtonGroup, 'push');
            app.NumButton7.FontSize = 20;
            app.NumButton7.FontWeight = 'bold';
            app.NumButton7.Position = [17 6 80 80];
            app.NumButton7.Text = '7';
            app.NumButton7.ButtonPushedFcn = createCallbackFcn(app, @NumButton7Pushed, true);

            % Create NumButton8
            app.NumButton8 = uibutton(app.ButtonGroup, 'push');
            app.NumButton8.FontSize = 20;
            app.NumButton8.FontWeight = 'bold';
            app.NumButton8.Position = [117 6 80 80];
            app.NumButton8.Text = '8';
            app.NumButton8.ButtonPushedFcn = createCallbackFcn(app, @NumButton8Pushed, true);

            % Create NumButton9
            app.NumButton9 = uibutton(app.ButtonGroup, 'push');
            app.NumButton9.FontSize = 20;
            app.NumButton9.FontWeight = 'bold';
            app.NumButton9.Position = [217 6 80 80];
            app.NumButton9.Text = '9';
            app.NumButton9.ButtonPushedFcn = createCallbackFcn(app, @NumButton9Pushed, true);

            % Create NumButton0
            app.NumButton0 = uibutton(app.ButtonGroup, 'push');
            app.NumButton0.FontSize = 20;
            app.NumButton0.FontWeight = 'bold';
            app.NumButton0.Position = [117 276 80 80];
            app.NumButton0.Text = '0';
            app.NumButton0.ButtonPushedFcn = createCallbackFcn(app, @NumButton0Pushed, true);

            % Create PlusButton
            app.PlusButton = uibutton(app.ButtonGroup, 'push');
            app.PlusButton.FontSize = 20;
            app.PlusButton.FontWeight = 'bold';
            app.PlusButton.Position = [317 186 80 80];
            app.PlusButton.Text = '+';
            app.PlusButton.ButtonPushedFcn = createCallbackFcn(app, @PlusButtonPushed, true);

            % Create MinusButton
            app.MinusButton = uibutton(app.ButtonGroup, 'push');
            app.MinusButton.FontSize = 20;
            app.MinusButton.FontWeight = 'bold';
            app.MinusButton.Position = [317 96 80 80];
            app.MinusButton.Text = '-';
            app.MinusButton.ButtonPushedFcn = createCallbackFcn(app, @MinusButtonPushed, true);

            % Create TimesButton
            app.TimesButton = uibutton(app.ButtonGroup, 'push');
            app.TimesButton.FontSize = 20;
            app.TimesButton.FontWeight = 'bold';
            app.TimesButton.Position = [317 6 80 80];
            app.TimesButton.Text = '*';
            app.TimesButton.ButtonPushedFcn = createCallbackFcn(app, @TimesButtonPushed, true);

            % Create DivideButton
            app.DivideButton = uibutton(app.ButtonGroup, 'push');
            app.DivideButton.FontSize = 20;
            app.DivideButton.FontWeight = 'bold';
            app.DivideButton.Position = [417 6 80 80];
            app.DivideButton.Text = '/';
            app.DivideButton.ButtonPushedFcn = createCallbackFcn(app, @DivideButtonPushed, true);

            % Create EqualsButton
            app.EqualsButton = uibutton(app.ButtonGroup, 'push');
            app.EqualsButton.FontSize = 20;
            app.EqualsButton.FontWeight = 'bold';
            app.EqualsButton.Position = [417 96 80 80];
            app.EqualsButton.Text = '=';
            app.EqualsButton.ButtonPushedFcn = createCallbackFcn(app, @EqualsButtonPushed, true);

            % Show the figure after all components are created
            app.UIFigure.Visible = 'on';
        end
    end

    % App creation and deletion
    methods (Access = public)

        % Construct app
        function app = CalculatorApp

            % Create UIFigure and components
            createComponents(app)

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

            % Execute the startup function
            runStartupFcn(app, @startupFcn)

            % Show the figure
            if nargout == 0
                clear app
                app.UIFigure.Visible = 'on';
            end
        end

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

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

这是一个简单的计算器应用程序，可以添加更多功能来提高其计算能力和用户体验。