Pointers in WinUI Radial Gauge

4 Jul 20226 minutes to read

Pointer is used to indicate values on an axis. The radial gauge control has four types of pointers:

Shape pointer
Content pointer
Needle pointer
Range pointer

All the pointers can be customized as needed. You can add multiple pointers to the gauge to point multiple values on the same scale. The value of the pointer is set using the Value property.

Multiple pointers

In addition to the default pointer, you can add n number of pointers to an axis by adding in the Pointers property.

XAML

<gauge:SfRadialGauge>
    <gauge:SfRadialGauge.Axes>
        <gauge:RadialAxis>
            <gauge:RadialAxis.Pointers>
                <gauge:RangePointer Value="30" />
                <gauge:ShapePointer Value="70" />
                <gauge:NeedlePointer Value="60" />
            </gauge:RadialAxis.Pointers>
        </gauge:RadialAxis>
    </gauge:SfRadialGauge.Axes>
</gauge:SfRadialGauge>

C#

SfRadialGauge sfRadialGauge = new SfRadialGauge();

RadialAxis radialAxis = new RadialAxis();
RangePointer rangePointer = new RangePointer { Value = 30 };
radialAxis.Pointers.Add(rangePointer);
ShapePointer shapePointer = new ShapePointer { Value = 70 };
radialAxis.Pointers.Add(shapePointer);
NeedlePointer needlePointer = new NeedlePointer { Value = 60 };
radialAxis.Pointers.Add(needlePointer);

sfRadialGauge.Axes.Add(radialAxis);

this.Content = sfRadialGauge;

Pointer dragging

Pointers can be dragged over the scale value. It can be achieved by clicking and dragging the pointer. To enable or disable the pointer drag, use the IsInteractive property.

XAML

<gauge:SfRadialGauge>
    <gauge:SfRadialGauge.Axes>
        <gauge:RadialAxis ShowTicks="False"
                          AxisLineFill="CornflowerBlue"
                          AxisLineWidth="30">
            <gauge:RadialAxis.Pointers>
                <gauge:ShapePointer Value="30"
                                     IsInteractive="True"
                                     MarkerOffset="-30"
                                     Background="Indigo" />
            </gauge:RadialAxis.Pointers>
        </gauge:RadialAxis>
    </gauge:SfRadialGauge.Axes>
</gauge:SfRadialGauge>

C#

SfRadialGauge sfRadialGauge = new SfRadialGauge();

RadialAxis radialAxis = new RadialAxis();
radialAxis.ShowTicks = false;
radialAxis.AxisLineFill = new SolidColorBrush(Colors.CornflowerBlue);
radialAxis.AxisLineWidth = 30;
sfRadialGauge.Axes.Add(radialAxis);

ShapePointer shapePointer = new ShapePointer();
shapePointer.Value = 30;
shapePointer.IsInteractive = true;
shapePointer.Background = new SolidColorBrush(Colors.Indigo);
shapePointer.MarkerOffset = -30;
radialAxis.Pointers.Add(shapePointer);

this.Content = sfRadialGauge;

Event

ValueChangeStarted - Occurs whenever the pointer starts to drag.

ValueChanging - Occurs before the current drag value gets updated as pointer value. The Cancel argument of ValueChangingEventArgs allows to restrict the update of current drag value as pointer value.

ValueChanged - Occurs whenever the pointer value is changed while dragging.

ValueChangeCompleted - Occurs once the dragging of the pointer gets completed.

XAML

<gauge:SfRadialGauge>
    <gauge:SfRadialGauge.Axes>
        <gauge:RadialAxis ShowTicks="False"
                          AxisLineFill="CornflowerBlue"
                          AxisLineWidth="30">
            <gauge:RadialAxis.Pointers>
                <gauge:ShapePointer Value="30"
                                     IsInteractive="True"
                                     MarkerOffset="-30"
                                     Background="Indigo" 
                                     ValueChanging="ShapePointer_ValueChanging"
                                     ValueChanged="ShapePointer_ValueChanged"/>
            </gauge:RadialAxis.Pointers>
        </gauge:RadialAxis>
    </gauge:SfRadialGauge.Axes>
</gauge:SfRadialGauge>

C#

private void ShapePointer_ValueChanging(object sender, ValueChangingEventArgs e)
{
    if (e.NewValue > 60)
    {
        e.Cancel = true;
    }
}

private void ShapePointer_ValueChanged(object sender, ValueChangedEventArgs e)
{

}