Q:

Do we have to explicitly recycle the bitmap if we don't need it?

Bitmap has a recycle method, but do we have to invoke it explicitly if we don't need it any more?
For example, an ImageView has a bitmap now. When user click a button, it will set a new bitmap to the ImageView.
Do we have to recycle the original bitmap before assign the new one?

A:

yes you have if you are targeting devices with Android older the 3.0. That's will avoid you to incour in the OutOfMemoryException.
Note: Before android 3 the Bitmap memory is allocated in the native heap. The java object will retains low memory from the GC perspective.

