Introduction of a new class properties inside its functions in App Designer.

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qwer ty 2018-5-29

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评论： Chris Portal 2018-11-15

I want the user to be able to add new UI components to the program.

For example, I want the user to enter code in TextArea that creates a new Panel (Voltage) and that can be accessed by using the app.Voltage.

The program has a TextArea and Button.

    classdef app < matlab.apps.AppBase
    % Properties that correspond to app components
    properties (Access = public)
        UIFigure  matlab.ui.Figure
        TextArea  matlab.ui.control.TextArea
        Button    matlab.ui.control.Button
    end
    methods (Access = private)
        % Button pushed function: Button
        function ButtonPushed(app, event)
            n = str2num(app.TextArea.Value{1}); % In the first line of TextArea writes the number of lines.
            eval([app.TextArea.Value{2:n};]); % All other lines are executed using the Eval function
        end
    end
    ...

I enter the code in TextArea and click on the button.

    2
    Voltage = uipanel(app.UIFigure)

A new panel is created.

But I can not address to it through other functions by using "Voltage" or "app.Voltage".

    % Button pushed function: Button2
    function Button2Pushed(app, event)
        Voltage.Title = '123';
    end

Nothing happens.

    % Button pushed function: Button2
    function Button2Pushed2(app, event)
        app.Voltage.Title = '123';
    end

Error: No appropriate method, property, or field 'Voltage' for class 'app'.

The last one is solved simply, it is necessary to add in Properties: "Voltage matlab.ui.container.Panel"

The problem in that what I can not do this, becouse I do not know the name and the UI component which will be added in advance.

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Answer 1

Chris Portal 2018-5-31

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https://ww2.mathworks.cn/matlabcentral/answers/403018-introduction-of-a-new-class-properties-inside-its-functions-in-app-designer#answer_322636

在 MATLAB Online 中打开

The way to do this would be to add a property to your app called something like “NewComponents”.

Every time you need to introduce a new component, create it and store the handle as a field of your NewComponents property. Something like:

NewComponents.Voltage = uipanel(app.UIFigure);

Then, whenever you need to access one of these components, access it using the property you created:

NewComponents.Voltage

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MILIND WANKHADE 2018-11-15

Try this

Chris Portal 2018-11-15

"qwer ty", the code you showed should work, but only if you defined NewComponents as a property of your app. If it's not a property of the app, then the panel handle isn't being saved anywhere once your Button 1 callback exits, which would explain why the code in Button 2's callback isn't doing anything.

The way to add a property to your app is to have this in your properties block:

properties (Access = public)
    NewComponents
end

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Introduction of a new class properties inside its functions in App Designer.

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Introduction of a new class properties inside its functions in App Designer.

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