iOS Healthkit reading workouts - ios

Question

Hi any one know how to fetch workouts data from HealthKit. i have seen in this tutorial http://www.raywenderlich.com/89733/healthkit-tutorial-with-swift-workouts it is in swift. i have tried in objective c based on that tutorial but getting results zero. there are questions for saving workouts but i want to read workouts data and display.
HKWorkoutType *workouttype = [HKWorkoutType workoutType];
HKWorkout *workout;
NSDate *startDate, *endDate;
NSDate *date1 = [NSDate date];
int daysTominus = -2;
startDate = [date1 dateByAddingTimeInterval:60*60*24*daysTominus];
int daysToAdd = 1;
NSDate *newDate1 = [date1 dateByAddingTimeInterval:60*60*24*daysToAdd];
endDate = newDate1;
workout = [HKWorkout workoutWithActivityType:HKWorkoutActivityTypeSwimming startDate:startDate endDate:endDate];
NSPredicate *predicate = [HKQuery predicateForObjectsFromWorkout:workout];
NSSortDescriptor *sortDescriptor = [NSSortDescriptor sortDescriptorWithKey:HKSampleSortIdentifierStartDate ascending:YES];
HKSampleQuery *sampleQuery = [[HKSampleQuery alloc] initWithSampleType:workouttype
predicate:predicate
limit:HKObjectQueryNoLimit
sortDescriptors:#[sortDescriptor]
resultsHandler:^(HKSampleQuery *query, NSArray *results, NSError *error)
{
if(!error && results){
for(HKQuantitySample *samples in results)
{
// your code here
NSLog(#"%#",samples);
}
}
}];
// Execute the query
[healthStore executeQuery:sampleQuery];

Answer 1

The problem seems to be your predicate.
This code works for me, I used running because I don't have swimming data but you can change it back to swimming:
-(void)retrieveWorkouts{
// 1. Predicate to read only running workouts
NSPredicate *predicate = [HKQuery predicateForWorkoutsWithWorkoutActivityType:HKWorkoutActivityTypeWalking];
// 2. Order the workouts by date
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc]initWithKey:HKSampleSortIdentifierStartDate ascending:false];
// 3. Create the query
HKSampleQuery *sampleQuery = [[HKSampleQuery alloc] initWithSampleType:[HKWorkoutType workoutType]
predicate:predicate
limit:HKObjectQueryNoLimit
sortDescriptors:#[sortDescriptor]
resultsHandler:^(HKSampleQuery *query, NSArray *results, NSError *error)
{
if(!error && results){
NSLog(#"Retrieved the following workouts");
for(HKQuantitySample *samples in results)
{
// your code here
HKWorkout *workout = (HKWorkout *)samples;
NSLog(#"%f",workout);
}
}else{
NSLog(#"Error retrieving workouts %#",error);
}
}];
// Execute the query
[healthStore executeQuery:sampleQuery];
}