change the caller's number during an incoming call

First I found a way to modify the called number during an outgoing call. I tried the same for the caller's number during an incoming call, but the only 开发者_运维知识库thing I can do is read the caller's number, not change it. Can someone give me a hint?

My code in on receive so far:

Bundle b = intent.getExtras();

Log.d(TAG, "Phone State: "+ b.getString(TelephonyManager.EXTRA_STATE));
incomingNumber = b.getString(TelephonyManager.EXTRA_INCOMING_NUMBER);
Log.d(TAG, "incoming number: "+ incomingNumber);

How could I proceed?

I don't think this is possible. This is because the default call activity and your receiver get the same intent. You are not really intercepting it. A work around is to display your own activity over the default one.