来自 HealthKit 的血糖值为零

Question

I've inserted some glucose data in my device health kit app, and now trying to retrieve these inserted data but I'm getting this error:

2015-05-17 11:33:08.056 HKTutorial[687:125911] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Attempt to convert incompatible units: mg/dL, mol<180.1558800000541>'

This the method code I'm using to retrieve the glucose data:

func updateGlucose(){    
let sampleType = HKSampleType.quantityTypeForIdentifier(HKQuantityTypeIdentifierBloodGlucose)


self.healthManager?.readMostRecentSample(sampleType, completion: { (mostRecentGluco, error) -> Void in

  if( error != nil )
  {
    println("Error reading blood sugar from HealthKit Store: \(error.localizedDescription)")
    return;
  }

  var glucoLocalizedString = self.kUnknownString;
  // 3. Format the weight to display it on the screen
  self.gluco = mostRecentGluco as? HKQuantitySample;

  if let mmol = self.gluco?.quantity.doubleValueForUnit(HKUnit.moleUnitWithMolarMass(HKUnitMolarMassBloodGlucose)) {
    let glucoFormatter = NSMassFormatter()
    glucoFormatter.forPersonMassUse = true;
    glucoLocalizedString = glucoFormatter.stringForObjectValue(mmol)!
  } else {
    println("error reading glucose data")
  }

  // 4. Update UI in the main thread
  dispatch_async(dispatch_get_main_queue(), { () -> Void in
    self.glucoLabel.text = glucoLocalizedString
    //self.updateBMI()

  });
});
}

The error breaks the code execution precisely at this line:

if let mmol = self.gluco?.quantity.doubleValueForUnit(HKUnit.moleUnitWithMolarMass(HKUnitMolarMassBloodGlucose)) {

Any ideas please?

Answer 1

The problem is that glucose is measured as a concentration but you are converting it to one volume x. The two units used are mmol/L and mg/dL . You are converting mg/dL to mol<180.1558800000541> , but instead you should be converting it to mmol/L .