Push notification.cs

public void PushNotification(string title, string message, string topic)
{
	if ((title == null) || (message == null) || (topic == null))
	{
		return;
	}

	var jGcmData = new JObject();

	jGcmData.Add("to", topic);

	var jDataNotification = new JObject();

	jDataNotification.Add("title", title);
	jDataNotification.Add("body", message);

	jGcmData.Add("content_available", true);
	jGcmData.Add("priority", "high");
	jGcmData.Add("notification", jDataNotification);

	SendToGCM(jGcmData);
}

private static void SendToGCM(JObject jGcmData)
{
	var url = new Uri("https://gcm-http.googleapis.com/gcm/send");
	try
	{
		using (var client = new HttpClient())
		{
			client.DefaultRequestHeaders.Accept.Add(
				new MediaTypeWithQualityHeaderValue("application/json"));

			client.DefaultRequestHeaders.TryAddWithoutValidation(
				"Authorization", "key=" + API_KEY);

			Task.WaitAll(client.PostAsync(url,
				new StringContent(jGcmData.ToString(), Encoding.UTF8, "application/json"))
				.ContinueWith(response =>
				{
					Console.WriteLine(response);
					Console.WriteLine("Message sent: check the client device notification tray.");
				}));
		}
	}
	catch (Exception e)
	{
		Console.WriteLine("Unable to send GCM message:");
		Console.Error.WriteLine(e.StackTrace);
	}
}