WPF, width of control change with window width change - wpf

Question

In WPF application, a grid panel with 3 columns as defined below
<Grid.ColumnDefinitions>
<ColumnDefinition Width="250"/>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="250"/>
</Grid.ColumnDefinitions>
There is a slider in the second column,the width of the slider needs to reduce when the window width reduces and at some point the slider needs to disappear (kind of responsive design).
I tried naming the second column and binding width of slider to "ActualWidth" property of the column, but it didn't help.
There is another way to handle window's size change event and do some adjustments. Any other simple way?
Update 1 :
Adding more of my code
<Grid VerticalAlignment="Top" HorizontalAlignment="Stretch">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="250"/>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="250"/>
</Grid.ColumnDefinitions>
<!-- some other elements in cell 0-->
<StackPanel Grid.Column="1" Orientation="Horizontal" HorizontalAlignment="Center">
<Button Width="22" Height="22">
<Image Source="a.png"/>
</Button>
<Slider MinWidth="100" MaxWidth="320" Width="320"/>
<Button Width="22" Height="22" >
<Image Source="b.png"/>
</Button>
<!-- some other elements in cell 2-->
</StackPanel>
</Grid>

Answer 1

That's because the ActualWidth of a ColumnDefinition is not a DependencyProperty and ColumnDefinition doesn't notify when this property has changed.
Instead try grouping all your controls in column 2 inside a Grid and bind to the ActualWidth of the grid.

Answer 2

Assuming the slider is a generic WPF slider control, then simply placing the slider inside the second column should work, as by default the control should fill all available column space. Perhaps a style you have applied to the slider is affecting this functionality? The slider should fill up the column, and shrink down into nothingness as the window/column resizes if you use this code
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="250"/>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="250"/>
</Grid.ColumnDefinitions>
<Slider Grid.Column='1'></Slider>
</Grid>
EDIT:
Based on your new code, perhaps this might be more what you are after?
<DockPanel VerticalAlignment="Top">
<!-- Elements in cell 0-->
<Grid Width="250" DockPanel.Dock="Left"/>
<!-- Elements in cell 2-->
<Grid Width="250" DockPanel.Dock="Right"/>
<!-- Cell 1-->
<DockPanel>
<Button DockPanel.Dock="Left" Width="22" Height="22">
<Rectangle Fill="Blue"/>
</Button>
<Button DockPanel.Dock="Right" Width="22" Height="22" >
<Rectangle Fill="Blue"/>
</Button>
<Slider/>
</DockPanel>
</DockPanel>
The slider will resize and disappear accordingly, and the slider position will remain consistent during the resizing of the window