---
uid: Uno.Features.Magnetometer
---

# 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](https://learn.microsoft.com/uwp/api/windows.devices.sensors.magnetometer).

* 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* Ensure to unsubscribe from the `ReadingChanged` event when you no longer need the readings, so that the sensor is no longer active to avoid unnecessary battery consumption.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

```csharp
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

```csharp
magnetometer.ReadingChanged -= Magnetometer_ReadingChanged;
```