How can I refresh the position of a Slider with Scroll event? - wpf

Question

I'm now tryin to scaling a image with mouse-wheel cmd.
and have some problems with refresh the position of slider position.
MainWindow.xaml
<Grid Grid.Row="1">
<Slider x:Name="slider_value" Value="{Binding Scale, Mode=TwoWay}" Maximum="3" Minimum="1"/>
</Grid>
<Other Grid>
<target obj want to scale>
<Grid.LayoutTransform>
<ScaleTransform ScaleX="{Binding ElementName=slider_value, Path=Value}"
ScaleY="{Binding ElementName=slider_value, Path=Value}"/>
</Grid.LayoutTransform>
</Other Grid>
MainViewModel.cs
private void ExecuteZoom(MouseWheelEventArgs e) {
if(e.Delta > 0) {
if(Scale>=3)
return;
Scale += 0.1;
}
if(e.Delta < 0) {
if(Scale<=1)
return;
Scale -= 0.1;
}
//((MainWindow)Application.Current.MainWindow).UpdateLayout();
//i thought this can be solved by above code but don't work
Debug.Print($"{Scale}");
}
I checked
the value of var Scale varies successfully with mouseWheel
the value of var Scale varies successfully with moving slider
the scale of target varies with slider moved by "Manually"
the value of var Scale successfully is changed
but the position of slider isn't affected, and also ScaleTransForm doesnt work.
thanks!
enter image description here
enter image description here