Android, how to use activitygroup with listview?

I have a tabbar in my app and there is a custom listview in the first tab page. i want to call new activity in the same tab when click the list items. I have searched two days and the only solution is to use activitygroup according to someone. But my first page class has "ext开发者_运维知识库ends ListActivity" code to list my array thus i can not add "extends activitygroup" to this class. How can i use activitygroup without adding extends code?