Why not await Animation.RunAsync when IterationCount is Infinite

[lindexi]

As you can see, the Animation.RunAsync will set the excpetion to TaskCompletionSource when the IterationCount is Infinite

Avalonia/src/Avalonia.Base/Animation/Animation.cs

Lines 342 to 343 in 2d51602

	if (this.IterationCount == IterationCount.Infinite)
	run.SetException(new InvalidOperationException("Looping animations must not use the Run method."));

I have other ideas, we can await the Animation.RunAsync when IterationCount is Infinite. And we can finish the RunAsync by cancellationToken be set.

By the ways, the other issues is when I receive the InvalidOperationException with Looping animations must not use the Run method., that I do not know what should I do.

[h0lg]

Similar question here: How do I start and stop an animation with IterationCount.Infinite, e.g. to animate an active remote search input?
I can get something to work by setting IterationCount to 0 intially, then to IterationCount.Infinite and use RunAsync with a cancellation token to start the animation, ignore the returned task and use the token to stop the animation. Also, resetting IterationCount to 0 seems to stop the animation.
The Looping animations must not use the Run method. error message still trips me up tho.

And even if this seems to work most of the time, there seems to be no way to observe (at code runtime) if the animation is currently running. That would be helpful to decide whether to let it run or restart such a longer living animation.

[maxkatz6]

How do I start and stop an animation with IterationCount.Infinite

Bind animation to a specific style selector, with a class-name or property activator for example.
And then toggle this class-name/property. It is how it's normally done with Avalonia XAML animations. You don't need to create and manually run animations in C#. And in case of infinite animations - you can't (unless you add it to styles in the same way as in XAML).

[lindexi]

@maxkatz6 Some logic request to control the animation start in the C# code.

[h0lg]

@maxkatz6 Thanks for your feedback! I'd like to avoid XAML in my project, but may try it for this corner case. I have however successfully created a style with a class selector and added the code-created (F# actually since I'm using it via Fabulous Avalonia) animation to it via Style.Animations. The animation starts if I add the trigger class - but doesn't stop reliably when removing it.

On another note, I've had another idea for working around the animation not stopping in my scenario, which is an AutoCompleteBox that I want to animate while its AsyncPopulator is running. I could periodically trigger the animation (with an IterationCount other than Infinite) manually while the AsyncPopulator is running.

[h0lg]

Some logic request to control the animation start in the C# code.

@lindexi That is hard to understand. Is that a question or a statement? Maybe try rephrasing.