我正在使用swift关注HealthKit的一些教程，我正在遵循的一个教程是如何从HealthKit中检索一些数据，如体重，身高年龄。本教程将介绍如何为每个记录检索最新记录，以下代码显示：
func readMostRecentSample(sampleType:HKSampleType , completion: ((HKSample!, NSError!) -> Void)!)
{
// 1. Build the Predicate
let past = NSDate.distantPast() as! NSDate
let now = NSDate()
let mostRecentPredicate = HKQuery.predicateForSamplesWithStartDate(past, endDate:now, options: .None)
// 2. Build the sort descriptor to return the samples in descending order
let sortDescriptor = NSSortDescriptor(key:HKSampleSortIdentifierStartDate, ascending: false)
// 3. we want to limit the number of samples returned by the query to just 1 (the most recent)
let limit = 1
// 4. Build samples query
let sampleQuery = HKSampleQuery(sampleType: sampleType, predicate: mostRecentPredicate, limit: limit, sortDescriptors: [sortDescriptor])
{ (sampleQuery, results, error ) -> Void in
if let queryError = error {
completion(nil,error)
return;
}
// Get the first sample
let mostRecentSample = results.first as? HKQuantitySample
// Execute the completion closure
if completion != nil {
completion(mostRecentSample,nil)
}
}
// 5. Execute the Query
self.healthKitStore.executeQuery(sampleQuery)
}
然后在其他类中，开发人员传递参数以获取所需的最新记录，以下代码显示了检索高度记录的方法：
func updateHeight()
{
// 1. Construct an HKSampleType for Height
let sampleType = HKSampleType.quantityTypeForIdentifier(HKQuantityTypeIdentifierHeight)
// 2. Call the method to read the most recent Height sample
self.healthManager?.readMostRecentSample(sampleType, completion: { (mostRecentHeight, error) -> Void in
if( error != nil )
{
println("Error reading height from HealthKit Store: \(error.localizedDescription)")
return;
}
var heightLocalizedString = self.kUnknownString;
self.height = mostRecentHeight as? HKQuantitySample;
// 3. Format the height to display it on the screen
if let meters = self.height?.quantity.doubleValueForUnit(HKUnit.meterUnit()) {
let heightFormatter = NSLengthFormatter()
heightFormatter.forPersonHeightUse = true;
heightLocalizedString = heightFormatter.stringFromMeters(meters);
}
// 4. Update UI. HealthKit use an internal queue. We make sure that we interact with the UI in the main thread
dispatch_async(dispatch_get_main_queue(), { () -> Void in
self.heightLabel.text = heightLocalizedString
self.updateBMI()
});
})
}
我为第一个创建了一个类似的方法，但几乎没有变化，所以我可以获得10个葡萄糖记录的数组：
func readAllGlucose(sampleType:HKSampleType , completion: (([HKSample!], NSError!) -> Void)!)
{
let now = NSDate()
let df = NSDateFormatter()
df.dateFormat = "yyyy-MM-dd"
let pastt = df.dateFromString("2015-05-18")
//let mostRecentPredicate = HKQuery.predicateForSamplesWithStartDate(past, endDate:now, options: .None)
let allreadings = HKQuery.predicateForSamplesWithStartDate(pastt, endDate: now, options: .None)
// 2. Build the sort descriptor to return the samples in descending order
let sortDescriptor = NSSortDescriptor(key:HKSampleSortIdentifierStartDate, ascending: false)
// 3. we want to limit the number of samples returned by the query to just 1 (the most recent)
let limit = 10
// 4. Build samples query
let sampleQuery = HKSampleQuery(sampleType: sampleType, predicate: allreadings, limit: limit, sortDescriptors: [sortDescriptor])
{ (sampleQuery, results, error ) -> Void in
if let queryError = error {
completion([nil],error)
return;
}
// Get the first sample
let allSamples = results as? [HKQuantitySample]
// Execute the completion closure
if completion != nil {
completion(allSamples!,nil)
}
}
// 5. Execute the Query
self.healthKitStore.executeQuery(sampleQuery)
}
然后我创建了另一种类似于updateHeight（）方法的方法，但当然做了必要的修改：
func updateLastGlucoRecords()
{
// 1. Construct an HKSampleType for weight
let sampleType = HKSampleType.quantityTypeForIdentifier(HKQuantityTypeIdentifierBloodGlucose)
// 2. Call the method to read the most recent weight sample
self.healthManager?.readAllGlucose(sampleType, completion: {([allReadings], error) -> Void in
if (error != nil) {
println("Error reading glucose readings from HealthKit Store: \(error.localizedDescription)")
return;
}
var glucoseLocalizedString = self.kUnknownString;
self.glucose = allReadings as? [HKQuantitySample]
for reading in readings {
if let record = reading.quantity {
glucoseLocalizedString = record
}
dispatch_async(dispatch_get_main_queue(), { () -> Void in
self.glucoReadings.append("\(glucoseLocalizedString)")
})
}
})
self.healthManager?.readMostRecentSample(sampleType, completion: { (mostRecentWeight, error) -> Void in
if( error != nil )
{
println("Error reading weight from HealthKit Store: \(error.localizedDescription)")
return;
}
var weightLocalizedString = self.kUnknownString;
// 3. Format the weight to display it on the screen
self.weight = mostRecentWeight as? HKQuantitySample;
if let kilograms = self.weight?.quantity.doubleValueForUnit(HKUnit.gramUnitWithMetricPrefix(.Kilo)) {
let weightFormatter = NSMassFormatter()
weightFormatter.forPersonMassUse = true;
weightLocalizedString = weightFormatter.stringFromKilograms(kilograms)
}
// 4. Update UI in the main thread
dispatch_async(dispatch_get_main_queue(), { () -> Void in
self.weightLabel.text = weightLocalizedString
self.updateBMI()
});
});
}
但不幸的是，我在这一行得到了两个错误：
self.healthManager?.readAllGlucose(sampleType, completion: {([allReadings], error) -> Void in
第一个错误：
[HKSample！]'不是'＆lt;＆gt;
的子类型
第二个错误：
使用未声明类型'allReadings'
我有另一个问题，如何从每个对象获取元数据，我想获取数据插入的日期和时间
如果有人有任何想法可以解决这个问题，我会感激并感激
提前致谢
答案 0 :(得分：1)
我遇到了同样的问题。请查看下面的代码。 1.） allReadings 错误是由于你没有传递HKSample数组的原因所以你必须写成：让allReadings：[HKSample！] 然后传递allReadings。
func readAllSample(sampleType:HKSampleType , completion: (([HKSample!], NSError!) -> Void)!)
{
let now = NSDate()
let past = now.dateByAddingTimeInterval(-10*24*60*60) as NSDate!
let mostRecentPredicate = HKQuery.predicateForSamplesWithStartDate(past, endDate:now, options: .None)
let sortDescriptor = NSSortDescriptor(key:HKSampleSortIdentifierStartDate, ascending: false)
let limit = 10
let sampleQuery = HKSampleQuery(sampleType: sampleType, predicate: mostRecentPredicate, limit: limit, sortDescriptors: [sortDescriptor])
{ (sampleQuery, results, error ) -> Void in
if(error == nil)
{
print(results)
}
}
self.healthKitStore.executeQuery(sampleQuery)
}