wpf progress bar bind to a listbox value

How can i move a progress bar value( i am simulating a car mph circular gauge using a progress bar) in accordance to a listbox value or combobox value? I am using a rectangle for the needle.

I can do it with a scroll bar( the value of the scrollbar makes the needle move) which is the code i will show. Instead of the value of the scroll bar i want to be able to have various speeds set in a listbox, combobox and when selected the progress bar / rectangle will move to that value.

Can this be done?

i will only show the code i think you need to see.. here is a pic of what i am talking about:

<Window.Resources>
<ControlTemplate x:Key="templateSpeedometer"
                     TargetType="ProgressBar">
    <ControlTemplate.Resources>
        <Style TargetType="Line">
        </Style>
    </ControlTemplate.Resources>


        <Canvas Width="0" Height="0" 
                    RenderTransform="1 0 0 1 0 50" Background="#FFF50D0D">

            <Rectangle Name="PART_Track" Width="180" />
            <Rectangle Fill="Black" Name="PART_Indicator" />



            <Polygon Points="5 2 5 -5 -75 0"
                         Stroke="Black" Fill="Gold">
                <Polygon.RenderTransform>
                    <RotateTransform 
                            Angle="{Binding ElementName=PART_In开发者_C百科dicator, 
                                            Path=ActualWidth}" />
                </Polygon.RenderTransform>
            </Polygon>
        </Canvas>
    </Border>
</ControlTemplate>
</Window.Resources>

<Grid x:Name="LayoutRoot">

    <StackPanel>
        <Grid Height="216" Name="grid1" Width="612">
            <ScrollBar Name="scroll" Orientation="Horizontal" Minimum="0" Maximum="100" SmallChange="1" LargeChange="10" Margin="8,235,4,-36" />
            <Border Background="#FF5EB6D8"  CornerRadius="25" Height="247" VerticalAlignment="Top" Margin="13,5,27,0">

            <ProgressBar Background="#FFD6E1E5" Margin="4,8,0,112" Maximum="100" Minimum="0" Template="{StaticResource templateSpeedometer}" Value="{Binding ElementName=scroll, Path=Value}" BorderBrush="#FF5EB6D8" OpacityMask="White" HorizontalAlignment="Left" Width="281" BorderThickness="5,1,1,1" Orientation="Vertical"/>
            </Border>

Yes, this can be done. If you have a list of values displayed within a ListBox (or ComboBox), you can bind to the selected value via the SelectedItem property.

For a potentially better overall design to your control, take a look at this blogpost:

http://www.scottlogic.co.uk/blog/colin/2011/02/a-circular-progressbar-style-using-an-attached-viewmodel/

I'd change the design of the templateSpeedometer by using the Value property (of the progressbar) and transforming the Value into an angle by using a ValueConverter.

<RotateTransform  
    Angle="{RelativeSource={RelativeSource TemplatedParent}, Path=Value, 
            Converter={StaticResource valueToAngleConverter}}" />                                    

That way you can bind the Value of the Gauge to a TrackBar, ScrollBar, ListBox.SelectedValue or whatever you like.

EDIT

I adjusted the code see here why I switched from TemplateBinding to Binding with RelativeSource.