Issue
I came across registerDefaultNetworkCallback and href="https://developer.android.com/reference/android/net/ConnectivityManager#registerNetworkCallback" rel="noreferrer">registerNetworkCallback while updating my Android app for API 28.
Having reviewed the documentation, I cannot find the difference between registering a network callback and registering a default network callback.
When will one use which?
Thanks in advance :)
Solution
As far as I understood, the difference between registerDefaultNetworkCallback
and registerNetworkCallback
it's only based on customisation.
registerDefaultNetworkCallback
works (surprisingly) as a default network listener, while registerNetworkCallback
it's more configurable. For example:
val connectivityManager = getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
val builder = NetworkRequest.Builder()
builder.addTransportType(NetworkCapabilities.TRANSPORT_CELLULAR)
val networkRequest = builder.build()
connectivityManager.registerNetworkCallback(networkRequest,
object : ConnectivityManager.NetworkCallback () {
override fun onAvailable(network: Network?) {
super.onAvailable(network)
Log.i("Test", "Network Available")
}
override fun onLost(network: Network?) {
super.onLost(network)
Log.i("Test", "Connection lost")
}
})
Here onAvailable
will be called only if the user connects to a cellular network (by connecting to WiFi it won't log anything). The same does onLost
when disconnecting from cellular network.
If we do it like this:
connectivityManager.registerDefaultNetworkCallback(object : ConnectivityManager.NetworkCallback() {
override fun onAvailable(network: Network?) {
super.onAvailable(network)
Log.i("Test", "Default -> Network Available")
}
override fun onLost(network: Network?) {
super.onLost(network)
Log.i("Test", "Default -> Connection lost")
}
})
Both functions work as default callbacks when the user is connecting (or disconnecting) to/from a network (it can be either WiFi or cellular).
These are just some very basic examples. Of course NetworkRequest
can have a lot of configurations by setting its capability
or transportType
. You can read more about these in the official documentation of NetworkRequest.
Answered By - MihaiV
Answer Checked By - David Marino (JavaFixing Volunteer)