Pointers in .NET MAUI Radial Gauge
17 Jul 20269 minutes to read
A pointer is used to indicate values on an axis. The radial gauge control has the following types of pointers:
All the pointers can be customized as needed. You can add multiple pointers to the gauge to point to multiple values on the same scale. The value of the pointer is set using the Value property.
NOTE
Prerequisite: Ensure that the required NuGet package is installed, the necessary namespaces are imported, and the SfRadialGauge control is properly configured in your application. For detailed setup and configuration instructions, refer to the Getting Started guide.
Multiple pointers
In addition to the default pointer, you can add any number of pointers to an axis by adding them to the Pointers collection property.
<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>SfRadialGauge sfRadialGauge = new SfRadialGauge();
RadialAxis radialAxis = new RadialAxis();
RangePointer rangePointer = new RangePointer { Value = 30 };
radialAxis.Pointers.Add(rangePointer);
ShapePointer markerPointer = new ShapePointer { Value = 70 };
radialAxis.Pointers.Add(markerPointer);
NeedlePointer needlePointer = new NeedlePointer { Value = 60 };
radialAxis.Pointers.Add(needlePointer);
sfRadialGauge.Axes.Add(radialAxis);
this.Content = sfRadialGauge;
Pointer interaction
Pointers can be dragged over the axis scale. This can be achieved by swipe or drag gestures. To enable or disable the pointer drag, use the IsInteractive property.
SfRadialGauge sfRadialGauge = new SfRadialGauge();
RadialAxis radialAxis = new RadialAxis();
radialAxis.ShowTicks = false;
radialAxis.AxisLineStyle.Fill = new SolidColorBrush(Colors.CornflowerBlue);
radialAxis.AxisLineStyle.Thickness = 30;
sfRadialGauge.Axes.Add(radialAxis);
ShapePointer markerPointer = new ShapePointer();
markerPointer.Value = 30;
markerPointer.IsInteractive = true;
markerPointer.Fill = new SolidColorBrush(Colors.Indigo);
markerPointer.Offset = -30;
radialAxis.Pointers.Add(markerPointer);
this.Content = sfRadialGauge;
Step frequency
The StepFrequency property is used to specify the interval between snap points while dragging the pointer.
For example, if the value of StepFrequency is 20, the pointer will not move continuously while dragging; instead, it will update in increments of 20.
NOTE
To work with the
StepFrequencyvalue, enable pointer interaction support.
<gauge:SfRadialGauge x:Name = "gauge">
<gauge:SfRadialGauge.Axes>
<gauge:RadialAxis ShowTicks = "False">
<gauge:RadialAxis.AxisLineStyle>
<gauge:RadialLineStyle Thickness = "30" Fill = "CornflowerBlue"/>
</gauge:RadialAxis.AxisLineStyle>
<gauge:RadialAxis.Pointers>
<gauge:ShapePointer Value = "30"
IsInteractive = "True"
StepFrequency = "5"
Offset = "-30"
Fill = "Indigo" />
</gauge:RadialAxis.Pointers>
</gauge:RadialAxis>
</gauge:SfRadialGauge.Axes>
</gauge:SfRadialGauge>SfRadialGauge sfRadialGauge = new SfRadialGauge();
RadialAxis radialAxis = new RadialAxis();
radialAxis.ShowTicks = false;
radialAxis.AxisLineStyle.Fill = new SolidColorBrush(Colors.CornflowerBlue);
radialAxis.AxisLineStyle.Thickness = 30;
sfRadialGauge.Axes.Add(radialAxis);
ShapePointer markerPointer = new ShapePointer();
markerPointer.Value = 30;
markerPointer.IsInteractive = true;
markerPointer.StepFrequency = 5;
markerPointer.Fill = new SolidColorBrush(Colors.Indigo);
markerPointer.Offset = -30;
radialAxis.Pointers.Add(markerPointer);
this.Content = sfRadialGauge;Events
ValueChangeStarted - Occurs whenever the pointer starts to drag.
ValueChanging - Occurs before the current drag value gets updated as the pointer value. The Cancel argument of ValueChangingEventArgs allows you to restrict the update of the current drag value.
ValueChanged - Occurs whenever the pointer value is changed while dragging.
ValueChangeCompleted - Occurs once the dragging of the pointer is completed.
<gauge:SfRadialGauge>
<gauge:SfRadialGauge.Axes>
<gauge:RadialAxis>
<gauge:RadialAxis.Pointers>
<gauge:ShapePointer Value = "30"
IsInteractive = "True"
ValueChanging = "MarkerPointer_ValueChanging"
ValueChanged = "MarkerPointer_ValueChanged"/>
</gauge:RadialAxis.Pointers>
</gauge:RadialAxis>
</gauge:SfRadialGauge.Axes>
</gauge:SfRadialGauge>SfRadialGauge sfRadialGauge = new SfRadialGauge();
RadialAxis radialAxis = new RadialAxis();
sfRadialGauge.Axes.Add(radialAxis);
ShapePointer markerPointer = new ShapePointer();
markerPointer.Value = 30;
markerPointer.IsInteractive = true;
markerPointer.ValueChanging += MarkerPointer_ValueChanging;
markerPointer.ValueChanged += MarkerPointer_ValueChanged;
radialAxis.Pointers.Add(markerPointer);
this.Content = sfRadialGauge;
// code omitted for brevity
private void MarkerPointer_ValueChanging(object sender, ValueChangingEventArgs e)
{
if (e.NewValue > 60)
{
e.Cancel = true;
}
}
private void MarkerPointer_ValueChanged(object sender, ValueChangedEventArgs e)
{
}