Animated spinner not turning?

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C#

I downloaded the code from How to write a loading circle animation in .NET?[^]
that is authored by Martin Gagne, and then loaded the code into my project. However, the Animated spinner does not Turning. In another word, when

this.loadingCircle = new MRG.Controls.UI.LoadingCircle();
loadingCircle.Active = true;

is called, the

protected override void OnPaint()

in LoadingCircle.cs is not fired (this method is fired only when the form is loaded).
I wish someone can help on this issue. Thanks.

What I have tried:

Animated spinner  Not Turning?