How to exit zoom mode by shortcut in my own GUI?

I wrote a GUI program, in which the zoom operation was frequently used. So I defined a KerPressFcn “ctrl+=” which was the "zoom on" operation. See the following function myfunc1.

But how should I define a shortcut to exit zoom mode? It seems that zoom off in the function just doesn't work.

But in the other hand, in the command window, if input

figure; plot(1:10)

a figure shows. Then in the command window, input

zoom on

the cursor is in zoom mode in the figure;

Back in the command window, type

zoom off

then in the figure, the cursor exits the zoom mode.

Why did NOT the same command zoom off in my own function work?

My own function: (I revised the code to be more specific)

function myfunc1(fig)
fig.KeyPressFcn = @zoomKeys;
hAxes = axes(fig);
% some codes
plot(1:10);
    function zoomKeys(~, event)
        if strcmp(event.Modifier, 'control')
            if ~strcmpi(event.Key, 'equal') % I want to exit the zoom mode.
                zoom(fig, 'off');
            end
            switch event.Key
                case 'equal' %'='
                    zoom(fig, 'on');
                case '0'
                    zoom(fig, 'out');
            end
        end
    end
end

[Rik]

I'm on mobile so I can't test the code, but you should probably use explicit handles in the zoom function.

[Albert Bing]

Use zoom(gcf, 'off') or zoom(fig, 'off') instead if just zoom off？

I tried, but it didn't work.