How to Transfer calls to voice mail in android?

Is there any way by which i can transfer calls to voice mail programmatically?? I am making an application 开发者_如何学Cfor android in which i will use this feature.

Detect using: CALL_STATE_RINGING or LISTEN_CALL_STATE

However, AFAIK, you cannot make API calls to the Telephony service which will allow forwarding to Voicemail.

You need to listen for incoming call. Disconnect the call. If voice mail facility is available on the device then it will ask user to leave voice mail.