HealthKit Namespace

The HealthKit namespace provides secure data storage and retrieval of health-related information.

Classes

HKActivitySummary	Summarizes user activity for a specific day.
HKActivitySummaryQuery	Gets HKActivitySummary instances that match an NSPredicate.
HKActivitySummaryType	Obect that is used to request permission to read HKActivitySummary objects.
HKAnchoredObjectQuery	An HKQuery that on its initial call returns the most recent result and in subsequent calls returns only data added after the initial call.
HKBiologicalSexObject	Returned by GetBiologicalSex(NSError).
HKBloodTypeObject	Returned by GetBloodType(NSError)
HKCategorySample	An HKSample whose value is one of an enumerated type.
HKCategoryType	An HKSampleType that currently has only one form: sleep analysis.
HKCategoryTypeIdentifierExtensions
HKCategoryTypeIdentifierKey	Defines the keys to identify HKCategoryTypes. Currently just the one key for sleep analysis.
HKCdaDocument	Contains the information that is represented in XML in a HealthKit store health document.
HKCdaDocumentSample	Contains the information that is represented in XML in a HealthKit store health document.
HKCharacteristicType	An HKObjectType that specifies a permanent aspect of the user.
HKCharacteristicTypeIdentifierExtensions
HKCharacteristicTypeIdentifierKey	Defines the constant name for a HKCharacteristicType.
HKClinicalRecord	A sample for clinical records.
HKClinicalType	A sample type for a clinical record.
HKClinicalTypeIdentifierExtensions
HKCorrelation	A correlation between two pieces of health data (for instance, blood pressure).
HKCorrelationQuery	An HKQuery that returns only data that had been stored with correlations. (Note: Systolic and diastolic blood pressure readings are not correlated.)
HKCorrelationType	An HKSampleType that specifies a correlation between two types of data (for instance, blood pressure).
HKCorrelationTypeIdentifierExtensions
HKCorrelationTypeKey	Defines the forms of HKCorrelation.
HKCumulativeQuantitySeriesSample	A cumulative data series.
HKDeletedObject	Represents samples that have been deleted from the store.
HKDetailedCdaErrors
HKDevice	Hardware that generates or consumes HealthKit data.
HKDevicePropertyKey	Holds keys whose constant values relate to properties of a HKDevice.
HKDocumentQuery	Queries for documents in the HealthKit store.
HKDocumentSample	Abstract HealthKit store health document.
HKDocumentType	Contains a constant that identifies the CDA document type.
HKDocumentTypeIdentifierExtensions
HKErrorCodeExtensions	Extension methods for the HealthKit.HKErrorCode enumeration.
HKFhirResource	Represents a Fast Healthcare Interoperability Resources (FHIR) resource.
HKFhirResourceTypeExtensions
HKFitzpatrickSkinTypeObject	Holds skin-type data.
HKHealthStore	MonoTouch.HealthKit.HKHealthStore A connection to the system-wide database of health-related information.
HKHealthStore.Notifications	Class that contains handlers for Health Kit store notifications.
HKMetadata	A key-value store for various types of health-related metadata.
HKMetadataKey	Defines the keys in the HKMetadata key-value dictionary.
HKObject	Base class to HKSample, which defines sampling data.
HKObjectType	Base class for types of data storable in the Health Kit database.
HKObserverQuery	An HKQuery that runs once initially and then is automatically executed when relevant data is added to the database .
HKPredicateKeyPath	Contains constants that represent keys that identify predicate key paths for selecting HealthKit values.
HKQuantity	Represents a measurable quantity of a certain type of unit, with a double value and a HKUnit type.
HKQuantitySample	A HKSample that has a magnitude (see Quantity).
HKQuantitySeriesSampleBuilder	Builds quantity sample series.
HKQuantitySeriesSampleQuery	Queries series data in a quantity sample.
HKQuantityType	A T:HKSampleType that represents either a cumulative or discrete sample.
HKQuantityTypeIdentifierExtensions
HKQuantityTypeIdentifierKey	Types of HKQuantityType.
HKQuery	Base class for querying Health Kit databases.
HKQueryAnchor	Represents the most recent sample that was returned by a previous anchored object query.
HKSample	A measurement of health information. Base class for HKQuantitySample and HKCategorySample.
HKSampleQuery	An HKQuery that retrieves HKSampleType data from the database.
HKSampleType	An HKObject that represents data that is sampled at a specific time or sampled over a time period.
HKSeriesBuilder
HKSeriesSample
HKSeriesType
HKSource	A provider of health data, such as a particular sensor or application.
HKSourceQuery	Class that represents a query for HealthKit data.
HKSourceRevision	Wraps HKSource, adding version information.
HKSourceRevisionInfo
HKStatistics	Provides basic statistical operations on health information.
HKStatisticsCollection	A group of related statistics (generally representing a time series).
HKStatisticsCollectionQuery	An HKQuery that produces a collection of statistics (for instance, number of steps per day for the previous month).
HKStatisticsQuery	An HKQuery that can calculate basic statistics (such as the sum and mean) on its constituent data.
HKUnit	Definitions and utility methods for manipulating measurements of mass, length, volume, and energy.
HKWheelchairUseObject	Contains an enumeration that describes wheelchair use.
HKWorkout	An HKSample that represents a physical workout.
HKWorkoutBuilder	Builds a workout from workout data as it is added.
HKWorkoutConfiguration	Contains workout configuration information.
HKWorkoutEvent	A pause or resumption of a workout.
HKWorkoutRoute
HKWorkoutRouteBuilder	A class for adding geographical data to a workout as the user's location changes.
HKWorkoutRouteQuery
HKWorkoutType	An HKSampleType representing a workout.

Enums

HKAuthorizationRequestStatus	Enumerates values that tell when an app should request user permission for access.
HKAuthorizationStatus	Enumerates the permission of the app to read or write health data.
HKBiologicalSex	Enumerates the biological sexes.
HKBloodGlucoseMealTime	Enumerates values that tell whether a blood glucose level was taken before or after a meal.
HKBloodType	Enumerates known blood types.
HKBodyTemperatureSensorLocation	Enumerates the positions at which a thermometer takes its reading.
HKCategoryTypeIdentifier	Enumerates the types of T:HealthKit.HKCategory; currently there is only the one form (Sleep Analysis).
HKCategoryValue	Contains a single value that indicates that a category value is not applicable to the category.
HKCategoryValueAppleStandHour	Enumerates whether the user stood or not during an hour.
HKCategoryValueCervicalMucusQuality	Enumerates the user's cervical mucus quality.
HKCategoryValueMenstrualFlow	Enumerates the amount of menstrual flow.
HKCategoryValueOvulationTestResult	Enumerates the results of an ovulation test.
HKCategoryValueSleepAnalysis	Enumerates the states of the slumberer: whether they are asleep or merely resting in bed.
HKCharacteristicTypeIdentifier	Enumerates the forms of HKCharacteristicType.
HKClinicalTypeIdentifier	Enumerates clinical record type identifiers.
HKCorrelationTypeIdentifier	Contains constants that identify HealthKit correlation types.
HKDocumentTypeIdentifier	Enumerates HealthKit document types.
HKErrorCode	Enumerates common errors made when accessing health data.
HKFhirResourceType	Enumerates Fast Healthcare Interoperability Resources (FHIR) types.
HKFitzpatrickSkinType	Enumerates skin types using the Fitzpatrick scale.
HKHeartRateMotionContext	Enumerates the possible activity-levels associated with a heart-rate sample.
HKHeartRateSensorLocation	Enumerates the locations at which a heart rate monitor is attached.
HKInsulinDeliveryReason	Enumerates the reasons for why insulin was provided.
HKMetricPrefix	Enumerates metric prefixes, e.g., Centi-, Deca-, Deci-. Used with factory methods of HKUnit.
HKQuantityAggregationStyle	Enumerates whether an HKQuantityType is a cumulative measure (for instance, "active energy burned") or a discrete value (such as "blood alcohol content").
HKQuantityTypeIdentifier	Enumerates the types of HKQuantityType.
HKQueryOptions	Enumerates options available for use with the GetPredicateForSamples(NSDate, NSDate, HKQueryOptions) method.
HKStatisticsOptions	Enumerates options applicable to HKStatisticsQuery and HKStatisticsCollectionQuery objets.
HKSwimmingStrokeStyle
HKUpdateFrequency	Enumerates the frequences for background delivery of data (see EnableBackgroundDelivery(HKObjectType, HKUpdateFrequency, Action<Boolean,NSError>)).
HKVO2MaxTestType	Enumerates the testing process used for establishing VO2 Max.
HKWeatherCondition	Enumerates weather types.
HKWheelchairUse	Enumerates constants that describe wheelchair use.
HKWorkoutActivityType	Enumerates various activities that are considered workouts.
HKWorkoutEventType	Enumerates events that can occur during a workout (Pause, Resume).
HKWorkoutSessionLocationType	Enumerates workout locations.
HKWorkoutSwimmingLocationType

Delegates

HKAnchoredObjectResultHandler	The completion handler for HKAnchoredObjectQuery(HKSampleType, NSPredicate, nuint, nuint, HKAnchoredObjectResultHandler2).
HKAnchoredObjectResultHandler2	Completion handler for anchored object queries.
HKAnchoredObjectUpdateHandler
HKCorrelationQueryResultHandler	Completion handler for HKCorrelationQuery.
HKHealthStoreGetRequestStatusForAuthorizationToShareHandler	Handler to pass to GetRequestStatusForAuthorizationToShare(NSSet<HKSampleType>, NSSet<HKObjectType>, HKHealthStoreGetRequestStatusForAuthorizationToShareHandler).
HKObserverQueryUpdateHandler	Update handler for HKObserverQuery objects.
HKQuantitySeriesSampleBuilderFinishSeriesDelegate	Completion handler for T:HealthKit.HKQuantitySeriesSampleBuilder.FinishSeries.
HKQuantitySeriesSampleQueryQuantityDelegate	A handler to pass to HKQuantitySeriesSampleQuery(HKQuantitySample, HKQuantitySeriesSampleQueryQuantityDelegate).
HKSampleQueryResultsHandler	Result handler for HKSampleQuery.
HKSourceQueryCompletionHandler	Completion handler for HKSourceQuery.
HKStatisticsCollectionEnumerator	Delegate handler for EnumerateStatistics(NSDate, NSDate, HKStatisticsCollectionEnumerator).
HKStatisticsCollectionQueryInitialResultsHandler	Results handler for SetInitialResultsHandler(HKStatisticsCollectionQueryInitialResultsHandler) and SetStatisticsUpdateHandler(HKStatisticsCollectionQueryInitialResultsHandler).
HKStatisticsCollectionQueryStatisticsUpdateHandler
HKStatisticsQueryHandler	Results handler for C:HKStatisticsQuery.
HKStoreSampleAddedCallback	Completion handler for AddSamples(HKSample[], HKWorkout, HKStoreSampleAddedCallback).
HKWorkoutBuilderCompletionHandler	Completion handler for adding metadata with HKWorkoutRouteQuery(HKWorkoutRoute, HKWorkoutRouteBuilderDataHandler).
HKWorkoutRouteBuilderAddMetadataHandler	Completion handler for adding metadata with HKWorkoutRouteQuery(HKWorkoutRoute, HKWorkoutRouteBuilderDataHandler).
HKWorkoutRouteBuilderDataHandler

Remarks

The Health Kit namespace, introduced in iOS 8, allows applications to record, track, and access health-related information to a common persistent store.

Provisioning, Permissions, and Profiles

To use Health Kit services, applications must be developed using an "Explicit App ID" and a provisioning profile that includes the explicit ID and Health Kit permissions.

In addition, applications must have an Entitlements.plist that contains the key com.apple.developer.healthkit of type Boolean with a value of true.

At runtime, the application must request access to the specific types of health data in which it is interested. The user will interact with a permissions dialog in the Health app that allows them fine-grained control over what health information they will allow.

var temperatureKey = HKQuantityTypeIdentifierKey.BodyTemperature;
var tempQuantityType = HKObjectType.GetQuantityType (temperatureKey);

var hks = new HKHealthStore ();
var success = await hks.RequestAuthorizationToShareAsync (new NSSet (new [] { tempQuantityType }), new NSSet ());

The result of the T:HealthKit.HKHealthStore.RequestAuthorizationtoShareAsync method indicates only that the user interacted with the permissions dialog, it does not indicate whether the user allowed any data sharing. For that, applications can use the GetAuthorizationStatus method:

var access = healthKitStore.GetAuthorizationStatus (HKObjectType.GetQuantityType (HKQuantityTypeIdentifierKey.HeartRate));
if (access.HasFlag (HKAuthorizationStatus.SharingAuthorized)) {
//...etc...

Creating and storing data

Once permissions have been granted, creating and storing data involves creating an HKSample of a particular HKSampleType and then calling SaveObject or SaveObjectAsync.

Exception-handling differences between async and non-async methods

Apple's philosophy regarding attempts to store or read non-permitted information is that such attempts should not cause runtime exceptions. Rather, methods such as RequestAuthorizationToShare and M:HealthKit.HKStore.SaveObject* are defined with completion callback handlers that are passed a non-null NSError argument in the case of an error. Application developers using such methods should take special care to check for success, as it is highly likely that users will be cautious about access to their health data.

In contrast, Xamarin's asynchronous versions of such methods (such as M:HealthKit.HKHealthStore.RequestAutorizationToShareAsync* and SaveObjectAsync) will throw an NSErrorException on failure or if the method is not allowed by the end user.

//Apple's philosophy: no exception
var myCurrentTemp = HKQuantity.FromQuantity (HKUnit.DegreeFahrenheit, 98.6);
var tempSample = HKQuantitySample.FromType (tempQuantityType, myCurrentTemp, new NSDate (), new NSDate (), new NSDictionary());

hks.SaveObject(tempSample, (success, error) => {
	if(error != null)
	{
   //...etc...

//Xamarin's philosophy: Lack of permissions raises exception
protected async void StoreAsync(HKHealthStore store, HKQuantitySample sample)
{
	try
	{
		var success = await store.SaveObjectAsync (sample);

	}catch(NSErrorException x)
	{
		Console.WriteLine (x);
	}
}

There are several types of T:HealthKit.HKObjecTypes:

HKCharacteristicType objects represent static characterics of the user, such as date of birth or blood type (see HKCharacteristicTypeIdentifierKey), while HKSampleType objects represent data that are sampled over time. As of iOS 8, there is only one type of HKCategorySample, which is SleepAnalysis. The large majority of Health Kit data types are defined in HKQuantityTypeIdentifierKey.

Manipulating data samples involves both an HKSampleType object and an HKSample to carry the data:

HKQuantitySamples may refer to an instantaneous measurement, in which case their P:HealthKit.HKQuantitySample.StartDate and P:HealthKit.HKQuantitySample.EndDate properties should be set to the same value. Other samples, such as step count, are measured over time and the start and end time should be set appropriately.

Data may have metadata associated with it. There are a number of predefined metadata keys in HKMetadataKey, but application developers are encouraged to created their own keys for metadata as well.

Units of measurement and conversion

Health Kit supports units of measurement in the categories of mass, length, volume, and energy. This support includes conversion of values between measurement systems (for instance, if a user prefers Fahrenheit degrees but has a sensor that reports its data in Celsius). This is automatically supported within the Health app, but explicit conversions are also possible, as shown in the following example:

var myFahrenheitTemp = HKQuantity.FromQuantity (HKUnit.DegreeFahrenheit, 98.6);
var myCelsiusTemp = myFahrenheitTemp.GetDoubleValue (HKUnit.DegreeCelsius);