使用Swift从HealthKit获取过去30天的bodyMass数据

import HealthKit

func getBodyMassData() {
    if HKHealthStore.isHealthDataAvailable() {
        let healthStore = HKHealthStore()
        
        guard let bodyMassType = HKObjectType.quantityType(forIdentifier: .bodyMass) else {
            print("Body Mass Type is no longer available in HealthKit")
            return
        }
        
        let startDate = Calendar.current.date(byAdding: .day, value: -30, to: Date())!
        let endDate = Date()
        let predicate = HKQuery.predicateForSamples(withStart: startDate, end: endDate, options: .strictStartDate)
        
        let query = HKSampleQuery(sampleType: bodyMassType, predicate: predicate, limit: HKObjectQueryNoLimit, sortDescriptors: nil) { (query, results, error) in
            guard let results = results as? [HKQuantitySample], error == nil else {
                print("Failed to fetch body mass data: \(String(describing: error))")
                return
            }
            
            for result in results {
                let quantity = result.quantity
                let unit = HKUnit.gramUnit(with: .kilo)
                let bodyMass = quantity.doubleValue(for: unit)
                print("Body Mass: \(bodyMass) kg")
            }
        }
        
        healthStore.execute(query)
    } else {
        print("HealthKit is not available on this device")
    }
}

getBodyMassData()