Magnetometer

Tip

This article covers Uno-specific information for Magnetometer. For a full description of the feature and instructions on using it, see Magnetometer Class.

• The Windows.Devices.Sensors.Magnetometer class allows measuring magnetic force affecting the device.

Supported features

Feature	Windows	Android	iOS	Web (WASM)	macOS	Linux (Skia)	Win 7 (Skia)
GetDefault	✔	✔	✔	✔	✔	✔	✔
ReadingChanged	✔	✔	✔	✔	✖	✖	✖
ReportInterval	✔	✔	✔	✔	✖	✖	✖

Using Magnetometer with Uno

• The GetDefault method is available on all targets and will return null on those which do not support Magnetometer or devices which do not have such sensor.
• Ensure to unsubscribe from the ReadingChanged event when you no longer need the readings, so that the sensor is no longer active to avoid unnecessary battery consumption.
• ReportInterval property on WASM is currently not supported directly. Uno uses an approximation in the form of raising the ReadingChanged event, only when enough time has passed since the last report. The event is raised a bit more often to make sure the gap caused by the filter is not too large, but this is in-line with the behavior of Windows' Magnetometer.
• DirectionalAccuracy is not reported on iOS, so it will always return Unknown.

Example

Capturing sensor readings

var magnetometer = Magnetometer.GetDefault();
magnetometer.ReadingChanged += Magnetometer_ReadingChanged;

private async void Magnetometer_ReadingChanged(Magnetometer sender, MagnetometerReadingChangedEventArgs args)
{
    // If you want to update the UI in some way, ensure the Dispatcher is used,
    // as the ReadingChanged event handler does not run on the UI thread.
    await Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
    {
        MagneticFieldX = args.Reading.MagneticFieldX;
        MagneticFieldY = args.Reading.MagneticFieldY;
        MagneticFieldZ = args.Reading.MagneticFieldZ;
        DirectionalAccuracy = args.Reading.DirectionalAccuracy;
        Timestamp = args.Reading.Timestamp.ToString("R");
    });
}

Unsubscribing from the readings

magnetometer.ReadingChanged -= Magnetometer_ReadingChanged;