Million thanks for your help, unikron. It does help me resolve this problem.
However, I have a tiny question about using a run-time created sprite. I just notice that it will create a lot copies of
SpriteCollection when adopt this workaround. I got 4 tabs in a single scene, so that user could switch between them. Each time user click a tab, it will create tens of SpriteCollections and
STILL ALIVE when user click other tab. The SpriteCollection keep accumulating in this level.
Would like to know if there is any way to handle those the auto-generated SpriteCollection?