问安卓(c2dm)推送通知错误

EN

        //Service emailid 
        var senderID = "myservice@gmail.com"; 
        var password = "myservice Password";
        //The application that is registering to receive messages
        var applicationID = "appID";

        service = new C2dmService(senderID, password, applicationID);

        service.Start();
        NameValueCollection extras;
        //for (int i = 0; i < 3; i++)
        //{
            extras = new NameValueCollection();
            //
            string registrationId = textBox4.Text;
            //An ID issued by the C2DM servers to the Android application that allows it to receive messages
            string collapseKey = "CKEY";
            string key = "count";
            string value = "5";
            extras.Add(key, value);

           //Queue up the message to be sent
            service.QueueMessage(registrationId, extras, collapseKey);
        //}
            service.Stop();------- its giving error here at the time of stoping the service