Create an array of distinct objects of handle class
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I want to store objects of a handle class in an array.
When using
for i=1:2
arr(i) = uilabel;
end
arrFor(1).Text = "textFor 1";
arr(2).Text = "textFor 2";
the objects in the array are distinct.
When using
arrDir(1:2) = uilabel;
arrDir(1).Text = "textDir 1";
arrDir(2).Text = "textDir 2";
both text will change to "textDir 2" which makes sense because uilabel is a handle class.
What is the syntax to avoid the for loop and diretly crating an array of distinct objects of a handle class?
2 Comments
Accepted Answer
Bruno Luong
on 19 Apr 2024
Edited: Bruno Luong
on 19 Apr 2024
Why not simply calling the constructor as many time as you need
arrDir = arrayfun(@(~)uilabel, 1:2);
arrDir(1).Text = "textDir 1";
arrDir(2).Text = "textDir 2";
arrDir(1).Text
4 Comments
Bruno Luong
on 19 Apr 2024
You could probably declare a subclass and over load the subsref subsasg methods and erase the handle copy behavior.
First of all I never did such thing. Second: it is just adding layer on layer and tweak the initial design pattern. It become dirty diffuclt to maibtain understand the code.
More Answers (1)
Fangjun Jiang
on 19 Apr 2024
As long as uilable() can only create a single object, there is no way to avoid the loop.
In arrDir(1:2) = uilabel, the same single handle was assigned to the two elements of arrDir.
What you should look for, is whatever the object class that you are working on, whether its creation method has the capability or syntax to create multiple objects in one shot.
3 Comments
Bruno Luong
on 19 Apr 2024
Edited: Bruno Luong
on 19 Apr 2024
Well a lot pf people use object (graphical) handles for decades, I don't see that often the need of deep copying handls or clonig them to an array.
If they do often the constructor is invoked as many as it needs, whereas it is manually unroll out, inside a for-loop or wrapped into an arrayfun/cellfun.
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