Generating an unknown ammount of Buttons in App Designer

Hello,

I'm trying to generate Buttons programmatically with the App Designer.

I have an Excel File, where all the names of the Buttons are listet, not knowing how many Buttons (or lines in Excel) will be needed.

I figured out how to create components with the App Designer programmtically:

https://de.mathworks.com/help/matlab/creating_guis/add-ui-components-to-app-designer-programmatically.html

So I tried many things, but none of them worked.

The problem is, that (as far as I understood) every Button (or other element) in the GUI needs his own variable. So I have to create new variables with the function eval, wich is, how I found out on every site here, absoulutly forbidden...

My first thought was to create an Array, but it didn't work:

Unable to perform assignment because dot indexing is not supported for variables of this type.

And heres the Code:

 A = [378 700 100 22];  %Position of the Button
            allKeys = string(keys(CellContOne)); %allKeys gets all the Buttonnames as a String
            UniButton = zeros(length(allKeys)); %An Array with the length of the List is created
            
            for i = 1:length(allKeys)   %For Loop to create the Buttons
                UniButton(i) = uibutton(app.UIFigure, 'state');  %Creating a Button
                UniButton(i).Position = A;  %Giving the Button a position
                UniButton(i).Text = allKeys(i); %Giving the Button it's Text
                b_text =  UniButton(i).Text;  %global Variable gets the Text
                b_value = UniButton(i).Value; %global Variable gets the Value
                UniButton(i).ValueChangedFcn = @app.mybuttonpress;  %Callback function
                A(2) = A(2) -25; %Position change for the next Button
                
            end

I also tried using just one variable for every Button, but it didn't work because the GUI wasn't able to figure out wich button was pressed (I need this information for the callback) The code looks the same, just without the index (i) and the line UniButton = zeros(length(allKeys));

Structures and Cell Arrays also didn't work for me.

I hope You can help me!

Answer 1

[xi]

You need to remove the line:

UniButton = zeros(length(allKeys));

In the callback function, you can retreive source.Text to determine which button is pressed and source.Value to determine the state of the pressed button:

function mybuttonpress(app,source,event)

source.Value

source.Text

end

[Ahmet Sahin]

Hi Xi,

thank You for Your help. I also didn't know about the source.___ thing, that also really helped me out.

Thank You!

Answer 2

[Dennis]

Hi,

your code should almost work, you need to remove the preallocation with zeros. You can let your loop run backwards instead:

 A = [378 700 100 22];  %Position of the Button
            allKeys = string(keys(CellContOne)); %allKeys gets all the Buttonnames as a String
           
            
            for i = length(allKeys):-1:1   %For Loop to create the Buttons
                UniButton(i) = uibutton(app.UIFigure, 'state');  %Creating a Button
                UniButton(i).Position = A;  %Giving the Button a position
                UniButton(i).Text = allKeys(i); %Giving the Button it's Text
                b_text =  UniButton(i).Text;  %global Variable gets the Text
                b_value = UniButton(i).Value; %global Variable gets the Value
                UniButton(i).ValueChangedFcn = @app.mybuttonpress;  %Callback function
                A(2) = A(2) -25; %Position change for the next Button
                
            end

[Ahmet Sahin]

Hi Dennis,

thank you very much, now everything works fine!

[Namita Gera]

@Dennis

I am struggling with the callback function on buttons and was hoping you could help.

I am creating a game in matlab app designer in which a player plays against the computer opponent. I want to code the CPU to press a button at random when it is its turn. For example, in TicTacToe the player plays against another player but in this case, the opponent is the CPU. The CPU is able to click buttons at random for example if there are 9 buttons it will press on any of those 9 randomly providing it has not been pressed already. I am not sure how to program this any help would be highly appreciated.

This is what i have so far

   if app.pl_move == 2
              n = randi(9)
              app.Button_(n).Text = "X";
              app.Button_(n).Enable = "off";
              app.pl_move = 1;
           end