public override void OnConnectionStateChange(BluetoothGatt gatt, GattStatus status, ProfileState newState)
{
if (newState == ProfileState.Connected)
{
_parent.OnStatusUpdated("Requesting MTU");
_gatt = gatt;
gatt.RequestMtu(138);
}
else if (newState == ProfileState.Disconnected && status != GattStatus.Success)
{
_handler.OnError();
}
}
protected override async Task <int> RequestMtuNativeAsync(int requestValue)
{
if (_gatt == null || _gattCallback == null)
{
Trace.Message("You can't request a MTU for disconnected devices. Device is {0}", State);
return(-1);
}
if (Build.VERSION.SdkInt < BuildVersionCodes.Lollipop)
{
Trace.Message($"Request MTU not supported in this Android API level");
return(-1);
}
return(await TaskBuilder.FromEvent <int, EventHandler <MtuRequestCallbackEventArgs>, EventHandler>(
execute : () => { _gatt.RequestMtu(requestValue); },
getCompleteHandler : (complete, reject) => ((sender, args) =>
{
if (args.Error != null)
{
Trace.Message($"Failed to request MTU ({requestValue}) for device {Id}-{Name}. {args.Error.Message}");
reject(new Exception($"Request MTU error: {args.Error.Message}"));
}
else
{
complete(args.Mtu);
}
}),
subscribeComplete : handler => _gattCallback.MtuRequested += handler,
unsubscribeComplete : handler => _gattCallback.MtuRequested -= handler,
getRejectHandler : reject => ((sender, args) =>
{
reject(new Exception($"Device {Name} disconnected while requesting MTU."));
}),
subscribeReject : handler => _gattCallback.ConnectionInterrupted += handler,
unsubscribeReject : handler => _gattCallback.ConnectionInterrupted -= handler
));
}