如何在Android中销毁触摸的Bitmap对象？

I am very new to Android programming, so I hope I make sense. I have a number of Bitmap objects that I would like to erase upon touch, and draw something else. What would be the best way to do it? I was originally thinking to destroy the object, but it may be redundant if I will be drawing another object anyways. Looking for a point in the right direction :)I am very new to Android programming, so I hope