Some control properties are not updated in real time as they are set? Version: 0.10.0-preview5

I just have cloned Slider -> SliderEx just to expose thumb with public getter, don’t know if i can get it by code but:

<uc:SliderEx
          Grid.Column="2"
          Name="Layer.Navigation.Slider"
          Minimum="0"
          Maximum="{Binding SliderMaximumValue}"
          Ticks="{Binding SliderMaximumValue}"
          Value="{Binding ActualLayer}"
          TickFrequency="1"
          TickPlacement="Outside"
          SmallChange="1"
          LargeChange="10"
          IsSnapToTickEnabled="True"
          Margin="0,5,0,5"
          HorizontalAlignment="Right"
          Orientation="Vertical"/>

public uint ActualLayer
        {
            get => _actualLayer;
            set
            {
                if (!SetProperty(ref _actualLayer, value)) return;
                OnPropertyChanged(nameof(CanGoDown));
                OnPropertyChanged(nameof(CanGoUp));
                OnPropertyChanged(nameof(ActualLayerTooltip));
                OnPropertyChanged(nameof(LayerNavigationTooltipMargin));
                OnPropertyChanged(nameof(LayerPixelCountStr));
                OnPropertyChanged(nameof(LayerBoundsStr));
                ShowLayer();
            }
        }

        public Thickness LayerNavigationTooltipMargin
        {
            get
            {
                double top = 0;
                if (LayerSlider?.Track != null)
                {
                    double trackerPos = LayerSlider.Track.Thumb.Bounds.Height / 2 + LayerSlider.Track.Thumb.Bounds.Top;
                    double halfTooltipHeight = LayerNavigationTooltipBorder.Bounds.Height / 2;
                    top = (trackerPos - halfTooltipHeight).Clamp(0,
                        LayerSlider.Bounds.Height - LayerNavigationTooltipBorder.Bounds.Height);
                    
                }
                return new Thickness(
                    0,
                    top,
                    5,
                    0);
            }
        }

Video of effect: https://youtu.be/4fbsOdm_SF4

Things i tried without success:

LayerSlider.InvalidateArrange();
LayerSlider.Track.InvalidateArrange();
LayerSlider.Track.Thumb.InvalidateArrange();
// Subscribe slider Value propertychanged and call OnPropertyChanged(nameof(LayerNavigationTooltipMargin));

[rstm-sf]

I’m new to WPF/Avalonia i come from WinForms, that’s why this is strange to me

@sn4k3 you can go through this tutorial without using reactiveui. Also you can look at this answer and this project. MVP and MVVM are friends with each other, so there is an MVPVM approach and it is very good for winforms

[timunie]

The need to use Dispatcher.UIThread seems to be required if property update are under override of Render method, while in others, for example in a button callback, that is not required.

Yeah, I think Render has it’s own thread in 11.0, so it’s expected that the event must be redirected to the UIThread.