How to make a phone call that don't show android system view?

I want to make a phone call an开发者_如何学Pythond by the code below:

Intent intent = new Intent(Intent.ACTION_CALL, Uri.parse("tel:123456789"));   
startActivity(intent);  

however, when I use those code to make a phone call, the android will show the system view and I don't see my view.How can I hide the system view and only show my view? Thank you !

Placing a call will always bring up the in-call screen. If you do not want that, you will need to create your own modified firmware and run it on your own devices.