Any way to control the render fps for Avalonia?

[laolarou726]

In WPF, you can do something like this to manually set the FPS for the application:

Timeline.DesiredFrameRateProperty.OverrideMetadata(typeof(Timeline),  
new FrameworkPropertyMetadata { DefaultValue = 30 });

Is there an equivalent thing in Avalonia?

[MinecraftYJQ]

It doesn't seem to be, but I haven't found it yet

[stevemonaco]

DevTools supports showing FPS as an overlay.

You can also enable the same overlay in your own app using the same approach DevTools uses:

Avalonia/src/Avalonia.Diagnostics/Diagnostics/ViewModels/MainViewModel.cs

Lines 87 to 116 in 46d4735

	private IRenderer? TryGetRenderer()
	=> _root switch
	{
	TopLevel topLevel => topLevel.Renderer,
	Controls.Application app => app.RendererRoot,
	_ => null
	};
	private bool GetDebugOverlay(RendererDebugOverlays overlay)
	=> ((TryGetRenderer()?.Diagnostics.DebugOverlays ?? RendererDebugOverlays.None) & overlay) != 0;
	private void SetDebugOverlay(RendererDebugOverlays overlay, bool enable,
	[CallerMemberName] string? propertyName = null)
	{
	if (TryGetRenderer() is not { } renderer)
	{
	return;
	}
	var oldValue = renderer.Diagnostics.DebugOverlays;
	var newValue = enable ? oldValue | overlay : oldValue & ~overlay;
	if (oldValue == newValue)
	{
	return;
	}
	renderer.Diagnostics.DebugOverlays = newValue;
	RaisePropertyChanged(propertyName);
	}

It may include some extra info you don't want in a real app. In that case, I'm not sure there's an approach besides using RequestAnimationFrame, Render override, etc and calculating+rendering FPS yourself.

[MinecraftYJQ]

I know. But I want to have a function directly to get it. and I wanted something that could directly control the FPS of the entire program.And the fetch you mentioned is only displayed on the screen, and only the debug mode is available

[stevemonaco]

You can enable the debug overlays even in release configuration builds. Being in charge of the FPS isn't really for the user app though it might be nice to have a low FPS mode for laptop/phone to save battery. That's the compositor's job that lives on its own render thread(s).