Compass Class

Reference

Definition

Namespace:: Windows.Devices.Sensors

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Edit

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.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
/// [Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
class Compass final

[Windows.Foundation.Metadata.ContractVersion(typeof(Windows.Foundation.UniversalApiContract), 65536)]
[Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
[Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
public sealed class Compass

Public NotInheritable Class Compass

Inheritance: Object Platform::Object IInspectable Compass

Attributes: ContractVersionAttribute MarshalingBehaviorAttribute ThreadingAttribute

Windows 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

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