How to detect emergency call only in Xamarin? - xamarin

Question

Is there a way to detect if the phone, at the call try moment, can only make emergency calls (using Xamarin)?

Answer 1

This is something platform specific. Unfortunaelty I don't know any plugin for this, so you have to use the native API in Xamarin.
On Android it is the TelephonyManager as shown here: https://stackoverflow.com/a/14355706/1489968 It's Java, but can be easily translated to C#:
public class MainActivity : Activity
{
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
SetContentView(Resource.Layout.Main);
var telMng = (TelephonyManager) GetSystemService(TelephonyService);
var myPhoneStateListener = new MyPhoneStateListener();
myPhoneStateListener.ServiceStateChanged += (s, e) => Console.WriteLine("State: {0}", e);
telMng.Listen(myPhoneStateListener, PhoneStateListenerFlags.ServiceState);
}
}
public class MyPhoneStateListener : PhoneStateListener
{
public event EventHandler<ServiceState> ServiceStateChanged;
public override void OnServiceStateChanged(ServiceState serviceState)
{
base.OnServiceStateChanged(serviceState);
ServiceStateChanged?.Invoke(this, serviceState);
}
}

Answer 2

On iOS: Not sure if that information is available, never have seen it exposed via the SDK... (maybe add iOS tag to this question, or ask an iOS only question, answer might be in ObjC/Swift but you can translate it)
On Android: The info you are looking for is contained within the ServiceState of the phone:
var callState = new ServiceState ();
switch (callState.State) {
case PhoneState.InService:
{
var uri = Android.Net.Uri.Parse ("tel:[phone]"); // Jim Rockford's number ;-)
var intent = new Intent (Intent.ActionDial, uri);
StartActivity (intent);
break;
}
case PhoneState.EmergencyOnly:
{
Toast.MakeText (this, "Emergency Calls Only", ToastLength.Long).Show();
break;
}
case PhoneState.OutOfService:
{
Toast.MakeText (this, "Out of Service", ToastLength.Long).Show();
break;
}
case PhoneState.PowerOff:
{
Toast.MakeText (this, "Cell/Modem Power Off", ToastLength.Long).Show();
break;
}
default:
{
Toast.MakeText (this, "Should never be shown on a real device", ToastLength.Long).Show();
break;
}
}
Ref: http://developer.android.com/reference/android/telephony/ServiceState.html
For testing on the emulator, you can set the state to denied via the adb shell:
voice denied
data denied
Ref: https://developer.android.com/tools/devices/emulator.html