我正在编写一个简单的应用程序,每当将新的健康率值写入 HealthKit 时,就可以从 HealthKit 监控心率(HKQuantityTypeIdentifierHeartRate)。
正如在 WWDC2015(第 203 场会议)上看到的,我正在使用HK锚定对象查询它应该适用于添加和删除对象。每当我启动应用程序时,我都会调用HKQuery对于最新的对象和执行查询效果很好!但即使样本存在,我也没有得到新的样本,但如果我将应用程序置于后台并再次置于前台,我将获得所有新的心率。这是一个错误吗?或者我该如何在不将应用程序置于后台和前台的情况下监测心率?
这是我正在使用的代码(所有内容都存储在 AppDelegate 中),我正在调用[self requestAccessDataTypes];
from didFinishLaunchingWithOptions:
[healthStore enableBackgroundDeliveryForType:sampleType frequency:HKUpdateFrequencyImmediate withCompletion:^(BOOL success, NSError *error) {}];
HKQuery *query = [self createHeartRateStreamingQuery:datum];
if (query) {
[healthStore executeQuery:query];
}
else
{
NSLog(@"workout can not start");
}
-(HKQuery*)createHeartRateStreamingQuery:(NSDate*)workoutStartDate
{
NSLog(@"%@ - createHeartRateStreamingQuery", [self class]);
if ([HKQuantityType quantityTypeForIdentifier:HKQuantityTypeIdentifierHeartRate]) {
HKQuantityType *quantityType = [HKQuantityType quantityTypeForIdentifier:HKQuantityTypeIdentifierHeartRate];
HKAnchoredObjectQuery * heartRateQuery = [[HKAnchoredObjectQuery alloc] initWithType:quantityType predicate:nil anchor:anchor limit:HKObjectQueryNoLimit resultsHandler:^(HKAnchoredObjectQuery * _Nonnull query, NSArray<__kindof HKSample *> * _Nullable sampleObjects, NSArray<HKDeletedObject *> * _Nullable deletedObjects, HKQueryAnchor * _Nullable newAnchor, NSError * _Nullable error) {
if (!error) {
anchor = newAnchor;
[self updateHeartRate:sampleObjects];
}
}];
heartRateQuery.updateHandler = ^void(HKAnchoredObjectQuery *query, NSArray<__kindof HKSample *> * __nullable addedObjects, NSArray<HKDeletedObject *> * __nullable deletedObjects, HKQueryAnchor * __nullable newAnchor, NSError * __nullable error)
{
if (!error) {
anchor = newAnchor;
[self updateHeartRate:addedObjects];
}
};
return heartRateQuery;
}
return nil;
}