Q:

Google cloud message(android) and window form(C#)

I want to send message and specify phone number from destop window application(my app on destop) to android application(my app) on mobile device by google cloud message.
So I think I must create a new web service so that I can push message from that service to google cloud message.How can I can do that?

A:

You will need the deviceID of your android device to send a notification to the device. So, you will need to design your web-service to have following functionality:

Receiving the deviceID from the android device.
Sending a message to the device whose deviceID is known to you. Your desktop app will need to talk to your web-service which can in-turn send message to google servers. GCM will handle sending notification. 

The part of obtaining the deviceId of a android device to sending message is explained well here:
https://developer.android.com/google/gcm/index.html

