2dx-lua怎么添加碰撞监听

Cocos2d-x Lua
#1 
    local eventDispatcher = self:getEventDispatcher()
    local contactListener = cc.EventListenerPhysicsContact:create()
contactListener:registerScriptHandler(function(physicsContact)
	printf('>> EVENT_PHYSICS_CONTACT_BEGIN')
	return true
end, cc.Handler.EVENT_PHYSICS_CONTACT_BEGIN)

contactListener:registerScriptHandler(function(physicsContact)
	printf('>> EVENT_PHYSICS_CONTACT_PRESOLVE')
end, cc.Handler.EVENT_PHYSICS_CONTACT_PRESOLVE)

contactListener:registerScriptHandler(function(physicsContact)
	printf('>> EVENT_PHYSICS_CONTACT_POSTSOLVE')
end, cc.Handler.EVENT_PHYSICS_CONTACT_POSTSOLVE)

contactListener:registerScriptHandler(function(physicsContact)
	printf('>> EVENT_PHYSICS_CONTACT_SEPERATE')
end, cc.Handler.EVENT_PHYSICS_CONTACT_SEPERATE)

eventDispatcher:addEventListenerWithSceneGraphPriority(contactListener, self)

我这样写只进了begin