how can i record lat/long datas on my session result

Your app needs to turn on GPS.  See the RecordSample in the SDK for a simple example of that in RecordSampleApp.mc

But that won't record the map data, will it? He'll need to record it (which is not a problem), but even then he won't see the map in Garmin Connect, because GC won't use the recorded data to display the map as they will be in some custom field, not the Garmin field for the same data

does it have any method to write a location data on Garmin field from custom app?

It works great to see the map in GC.  I've been doing it for years.  When you enable GPS, the data is automatically recorded in the fit file.

You can also try one of my apps that records an activity with GPS data.  It's much more complex than the sample, and there are things like you can't start recording until you get good GPS (depending on conditions, that could take a couple minutes) and on one of the dozen or so screens you'll either see a breadcrumb trail, or if the device has onboard maps, the actual map of your walk/hike.

https://apps.garmin.com/apps/116a5b59-29ae-4397-a70e-907d7e5f8e44

i wrote a code on Delegate before session started

What I do in onPosition is fairly simple and that's to save the quality/accuracy, and set a flag when the accuracy is good enough to start recording. I save off a few things so I can display/use them it on various screens in Hike2 and draw the breadcrumb trail if needed.

The recording takes care of itself.

flocsy🤠 said:

But that won't record the map data, will it? He'll need to record it (which is not a problem), but even then he won't see the map in Garmin Connect, because GC won't use the recorded data to display the map as they will be in some custom field, not the Garmin field for the same data

Basic activity data like GPS (if available), elevation, and HR are automatically recorded (as native fields) when you record an activity in a device app using ActivityRecording.createSession() (as in the OP).

As jim_m_58 said, the only missing piece here is that the app needs to explicitly turn on GPS.

Does anyone know if it is possible to record a session and only record GPS data if it is of a certain quality. ie Can I record heart rate, steps etc, but prevent GPS data from being recorded in the FIT file if the Quality is not Position.QUALITY_USABLE || Position.QUALITY_GOOD, and if does become USABLE or GOOD at some point, then to allow that data to be recorded ?