Compass Class

Definition

Represents a compass sensor.

This sensor returns a heading with respect to Magnetic North and, possibly, True North. (The latter is dependent on the system capabilities.)

For an example implementation, see the compass sample.

public ref class Compass sealed
/// [Windows.Foundation.Metadata.ContractVersion(Windows.Foundation.UniversalApiContract, 65536)]
/// [Windows.Foundation.Metadata.DualApiPartition(version=100794368)]
/// [Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
/// [Windows.Foundation.Metadata.Static(Windows.Devices.Sensors.ICompassStatics, 65536, Windows.Foundation.UniversalApiContract)]
/// [Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
class Compass sealed
/// [Windows.Foundation.Metadata.ContractVersion(Windows.Foundation.UniversalApiContract, 65536)]
/// [Windows.Foundation.Metadata.DualApiPartition(version=100794368)]
/// [Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
/// [Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
/// [Windows.Foundation.Metadata.Static(Windows.Devices.Sensors.ICompassStatics, 65536, "Windows.Foundation.UniversalApiContract")]
class Compass sealed
/// [Windows.Foundation.Metadata.ContractVersion(Windows.Foundation.UniversalApiContract, 65536)]
/// [Windows.Foundation.Metadata.DualApiPartition(version=100794368)]
/// [Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
/// [Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
/// [Windows.Foundation.Metadata.Static(Windows.Devices.Sensors.ICompassStatics, 65536, "Windows.Foundation.UniversalApiContract")]
/// [Windows.Foundation.Metadata.Static(Windows.Devices.Sensors.ICompassStatics2, 327680, "Windows.Foundation.UniversalApiContract")]
class Compass sealed
[Windows.Foundation.Metadata.ContractVersion(typeof(Windows.Foundation.UniversalApiContract), 65536)]
[Windows.Foundation.Metadata.DualApiPartition(version=100794368)]
[Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
[Windows.Foundation.Metadata.Static(typeof(Windows.Devices.Sensors.ICompassStatics), 65536, typeof(Windows.Foundation.UniversalApiContract))]
[Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
public sealed class Compass
[Windows.Foundation.Metadata.ContractVersion(typeof(Windows.Foundation.UniversalApiContract), 65536)]
[Windows.Foundation.Metadata.DualApiPartition(version=100794368)]
[Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
[Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
[Windows.Foundation.Metadata.Static(typeof(Windows.Devices.Sensors.ICompassStatics), 65536, "Windows.Foundation.UniversalApiContract")]
public sealed class Compass
[Windows.Foundation.Metadata.ContractVersion(typeof(Windows.Foundation.UniversalApiContract), 65536)]
[Windows.Foundation.Metadata.DualApiPartition(version=100794368)]
[Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
[Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
[Windows.Foundation.Metadata.Static(typeof(Windows.Devices.Sensors.ICompassStatics), 65536, "Windows.Foundation.UniversalApiContract")]
[Windows.Foundation.Metadata.Static(typeof(Windows.Devices.Sensors.ICompassStatics2), 327680, "Windows.Foundation.UniversalApiContract")]
public sealed class Compass
Public NotInheritable Class Compass
Inheritance
Compass
Attributes

Windows 10 requirements

Device family
Windows 10 (introduced in 10.0.10240.0)
API contract
Windows.Foundation.UniversalApiContract (introduced in v1.0)

Remarks

Sensor data is provided relative to the device's fixed sensor coordinate system, and is independent of display orientation. For applications that rely on sensor data for input control or to manipulate elements on the screen, the developer must take current display orientation into account and compensate the data appropriately. For more info about the sensor coordinate system, see Sensor data and display orientation.

The following example demonstrates how a UWP app built with XAML and C# uses the GetDefault method to establish a connection to a compass. If no integrated compass is found, the method will return a null value.

_compass = Compass.GetDefault();

The following example demonstrates how a UWP app built with XAML registers a ReadingChanged event handler.

private void ScenarioEnable(object sender, RoutedEventArgs e)
{
    if (_compass != null)
    {
        // Establish the report interval
        _compass.ReportInterval = _desiredReportInterval;

        Window.Current.VisibilityChanged += new WindowVisibilityChangedEventHandler(VisibilityChanged);
        _compass.ReadingChanged += new TypedEventHandler<Compass, CompassReadingChangedEventArgs>(ReadingChanged);

        ScenarioEnableButton.IsEnabled = false;
        ScenarioDisableButton.IsEnabled = true;
    }
    else
    {
        rootPage.NotifyUser("No compass found", NotifyType.StatusMessage);
    }
}

The following example shows the ReadingChanged event handler.

async private void ReadingChanged(object sender, CompassReadingChangedEventArgs e)
{
    await Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
    {
        CompassReading reading = e.Reading;
        ScenarioOutput_MagneticNorth.Text = String.Format("{0,5:0.00}", reading.HeadingMagneticNorth);
        if (reading.HeadingTrueNorth != null)
        {
            ScenarioOutput_TrueNorth.Text = String.Format("{0,5:0.00}", reading.HeadingTrueNorth);
        }
        else
        {
            ScenarioOutput_TrueNorth.Text = "No data";
        }
    });
}

Version history

Windows version SDK version Value added
1709 16299 FromIdAsync
1709 16299 GetDeviceSelector
1709 16299 MaxBatchSize
1709 16299 ReportLatency
2004 19041 ReportThreshold

Properties

DeviceId

Gets the device identifier.

MaxBatchSize

Gets the maximum number of events that can be batched by the sensor.

MinimumReportInterval

Gets the minimum report interval supported by the compass.

ReadingTransform

Gets or sets the transformation that needs to be applied to sensor data. Transformations to be applied are tied to the display orientation with which to align the sensor data.

ReportInterval

Gets or sets the current report interval for the compass.

ReportLatency

Gets or sets the delay between batches of sensor information.

ReportThreshold

Gets the CompassDataThreshold for the compass sensor.

Methods

FromIdAsync(String)

Asynchronously obtains the sensor from its identifier.

GetCurrentReading()

Gets the current compass reading.

GetDefault()

Returns the default compass.

GetDeviceSelector()

Gets the device selector.

Events

ReadingChanged

Occurs each time the compass reports a new sensor reading.

Applies to

See also