Slider + Zoom.Width + RadCartesianChart

[Kyle]

I have a Slider control bound (TwoWay) to the Zoom.Width property of a RadCartesianChart control.  When I zoom in and out with the scrollwheel on my mouse, the Slider automatically changes (as it should).  But when I try to use the slider to zoom thechart in and out, nothing happens.  The slider won't move.  Is there something I am missing?​
<Slider Name="Slider"
    Grid.Column="0"
    Margin="2"
    Orientation="Vertical"
    Minimum="1"
    Maximum="100"
    Value="{Binding ElementName=Chart, Path=Zoom.Width, Mode=TwoWay}"/>

<telerik:RadCartesianChart Name="Chart"
    Grid.Column="1"
    Palette="{Binding ChartPalette}"
    HorizontalZoomRangeStart="{Binding HorizontalZoomRangeStart, Mode=TwoWay}"
    HorizontalZoomRangeEnd="{Binding HorizontalZoomRangeEnd, Mode=TwoWay}">

    ...

</telerik:RadCartesianChart>

[Peshito]

Hi Kyle,

The Zoom property of the chart is of type Size which is a struct. This means that your binding gets a copy of struct since structs are passed by value to methods. In order to get the slider changing zoom's width of the chart attach to slider's ValueChanged event of the slider and update the WIdth and Height of the zoom.

For instance:

private void Slider_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
{
    Chart.Zoom = new Size()
    {
        Width = this.Slider.Value,
        Height = this.Chart.Zoom.Height
    };
}

You can further customize the method and update the PanOffset as well.

Hope this helps.

Regards,
Peshito
Telerik