Revert "footer"

This reverts commit 1f85a6a1e1743930e57348e8d127070ebdf20c97.
Revert "footer"

This reverts commit 8479e0cdf488f16036d484c43594625fa371ef9f.
Revert "on last item visible"

This reverts commit f374c41bc419e51c9a34cabcb7759ea7357f7b18.
footer
优化内存