Pointers in WinUI Radial Gauge

20 May 20216 minutes to read

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

Marker 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:MarkerPointer 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);
MarkerPointer markerPointer = new MarkerPointer { Value = 70 };
radialAxis.Pointers.Add(markerPointer);
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:MarkerPointer 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);

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

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:MarkerPointer Value="30"
                                     IsInteractive="True"
                                     MarkerOffset="-30"
                                     Background="Indigo" 
                                     ValueChanging="MarkerPointer_ValueChanging"
                                     ValueChanged="MarkerPointer_ValueChanged"/>
            </gauge:RadialAxis.Pointers>
        </gauge:RadialAxis>
    </gauge:SfRadialGauge.Axes>
</gauge:SfRadialGauge>

c#

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

private void MarkerPointer_ValueChanged(object sender, ValueChangedEventArgs e)
{

}