Fix for button handlers mixed up between instances (#316).
Fix for button handlers mixed up between instances (#316).

Julienedies/mobiscroll,xuyansong1991/mobiscroll,mrzzcn/mobiscroll,Julienedies/mobiscroll,jeancroy/mobiscroll,xuyansong1991/mobiscroll,mrzzcn/mobiscroll,jeancroy/mobiscroll