State button callback- break while loop?
显示 更早的评论
Hi,
I'm trying to loop through hundreds of frames in a file with the push of a state button and the use of a slider in AppDesigner. With the code below, what I've managed so far is to get it to loop until the end of all frames and then stop.
What I'd like it to do further, however, is to loop continuously until the button is pressed, and stop looping by breaking the while loop when the button is un-pressed.
I would greatly appreciate all your tips and suggestions!
Thanks!
v = app.pswitch.Value;
switch v
case 0
% do nothing
case 1
j = get(app.Slider, 'Value');
while j < 300 % (number of frames)
if v == 1
% do this:
pause(1/1000)
j = get(app.Slider, 'Value');
app.Spinner.Value = j+1; % go to the next frame
app.Slider.Value = j+1; % go to the next frame
app.I = imshow(app.testrgb(:,:,3,j+1), [300 1300],...
'Parent', app.UIAxes); % display the next frame
end
end
app.Spinner.Value = 1;
app.Slider.Value = 1;
set(app.pswitch, 'Value', 0)
otherwise
% do nothing
end
采纳的回答
Rik
2020-9-3
0 个投票
In general the solution to this is to use a flag that is controlled by your button. Then inside the while loop you check for that flag (a simple if flag,break,end will do).
更多回答（1 个）
Mohammad Sami
2020-9-3
You can try something like this.
app.STOPButton.Enable = true;
app.STOPButton.Value = 0;
while(somecondition)
% do something
if(app.STOPButton.Value == 1)
break;
end
end
app.STOPButton.Enable = false;
app.STOPButton.Value = 0;
6 个评论
Veena Chatti
2020-9-3
Rik
2020-9-3
I don't have much experience with AppDesigner, but I would have expected the code from Mohammad to work. You might need drawnow in your while loop to force Matlab to execute queued callbacks.
Mohammad Sami
2020-9-3
编辑：Mohammad Sami
2020-9-3
Are you using a state button ? The code is written for use with state button.
If that does not work, you can use drawnow as suggested by Rik.
Veena Chatti
2020-9-3
Rik
2020-9-3
The theoretical limit would be eps. As a practical limit I would suggest 30ms.
It isn't hard to test this, just use a loop to make the time smaller until tic,toc is telling you the pause is much longer than the time you asked for. I you want I can write some code for you. I'm currently on mobile so writing an example is more challenging.
Veena Chatti
2020-9-12
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