ArcScaleNeedle.Options Property

Gets or sets the options that allow you to customize the needle's shape and position on a Circular scale.

Namespace: DevExpress.Xpf.Gauges

Assembly: DevExpress.Xpf.Gauges.v20.2.dll

Declaration

public ArcScaleNeedleOptions Options { get; set; }
Public Property Options As ArcScaleNeedleOptions

Property Value

Type Description
ArcScaleNeedleOptions

An ArcScaleNeedleOptions object that contain the settings for the needle.

Remarks

Use the ArcScaleNeedleOptions object returned by the Options property to customize different needle settings (e.g. the ArcScaleNeedleOptions.StartOffset and ArcScaleNeedleOptions.EndOffset properties to set the required position of the Needle on a Circular scale).

Examples

The following example illustrates a gauge that looks and behaves like a typical 'knob' element of a real-life dashboard. In this case we demonstrate how to create, for example, a realistic volume control.

To provide its appearance, we use custom templates for an arc scale's needle and layer elements. For your convenience, these templates are stored in the KnobRestoreDictionary.xaml file, and named OscilloscopeNeedleTemplate and OscilloscopeScaleLayerTemplate. They can be easily re-used in your application.

This knob also provides the capability to interactively modify its value via mouse clicks. To enable this, the ValueIndicatorBase.IsInteractive property of a gauge's needle is set to True to enable its interactivity.

Finally, below the knob-like gauge, there is a Label control, which is bound to the ValueIndicatorBase.Value property of a needle to display the current volume set by knob.

View Example

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                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <ControlTemplate x:Key="OscilloscopeNeedleTemplate">
        <Grid RenderTransformOrigin="0, 0.5" Width="100" Height="100" Margin="-50,0,0,0">
            <Ellipse Margin="6" Fill="Transparent"/>
            <Grid x:Name="Needle" Margin="0">
                <Ellipse Width="7" Height="7" Fill="#FF1B5D83" HorizontalAlignment="Right" Margin="0,0,15,0"/>
                <Ellipse Width="5" Height="5" Fill="#FF3286AD" HorizontalAlignment="Right" Margin="0,0,16,0"/>
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                      HorizontalAlignment="Center" Height="85" Margin="0" VerticalAlignment="Center" Width="85" Opacity="0.35"/>
            </Grid>
        </Grid>
    </ControlTemplate>
    <ControlTemplate x:Key="OscilloscopeScaleLayerTemplate">
        <Grid RenderTransformOrigin="0.5, 0.5" Width="100" Height="100">
            <Ellipse Fill="White" Margin="0,1,0,-1" Opacity="0.9"/>
            <Ellipse Fill="#FFAEB3BE" Margin="0,0,0,1"/>
            <Ellipse Grid.Column="1" Margin="0,1,0,0">
                <Ellipse.Fill>
                    <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                        <GradientStop Color="#FFCBCFD5" Offset="0"/>
                        <GradientStop Color="#FFF5F6F7" Offset="1"/>
                    </LinearGradientBrush>
                </Ellipse.Fill>
            </Ellipse>
            <Path Stretch="Fill" Data="F1 M 798,507C 798,540.137 784.121,567 767,567C 749.879,567 736,540.137 736,507L 798,507 Z " 
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                <Path.Fill>
                    <RadialGradientBrush Center="0.5,0.002" GradientOrigin="0.5,0.002" RadiusY="0.688" RadiusX="0.533">
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                        <GradientStop Color="#002D344B" Offset="1"/>
                        <GradientStop Color="#CC2D344B" Offset="0.8"/>
                    </RadialGradientBrush>
                </Path.Fill>
            </Path>
            <Ellipse Margin="6">
                <Ellipse.Fill>
                    <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                        <GradientStop Color="#FFBCC0CA" Offset="0"/>
                        <GradientStop Color="#FF5C6378" Offset="1"/>
                    </LinearGradientBrush>
                </Ellipse.Fill>
            </Ellipse>
            <Ellipse Margin="7">
                <Ellipse.Fill>
                    <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                        <GradientStop Color="#FFFAFAFC" Offset="0"/>
                        <GradientStop Color="#FF9499AB" Offset="1"/>
                    </LinearGradientBrush>
                </Ellipse.Fill>
            </Ellipse>
            <Ellipse Margin="10" Fill="White"/>
            <Ellipse Margin="10,11,10,10">
                <Ellipse.Fill>
                    <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                        <GradientStop Color="#FFE9EBEE" Offset="0"/>
                        <GradientStop Color="#FFCFD4DA" Offset="1"/>
                    </LinearGradientBrush>
                </Ellipse.Fill>
            </Ellipse>
        </Grid>
    </ControlTemplate>
</ResourceDictionary>
See Also