怎么测都是began -> moved -> end，移出img的区域也还是end。
cancelled怎么触发不了呢？
local img = display.newSprite("80x40button_n.png", 100, 100, params):addTo(self)
img:setTouchEnabled(true)
img:addNodeEventListener(cc.NODE_TOUCH_EVENT, function(event)
if event.name ~= "moved" then
print(event.name)
end
if event.name == "began" then
print("点击开始", event.x, event.y, event.prevX, event.prevY)
return true
elseif event.name == "ended" then
print("完成点击:", event.x, event.y)
elseif event.name == "moved" then
print("移动偏移量: ", event.x-event.prevX, event.y-event.prevY)
elseif event.name == "cancelled" then
print("点击取消")
end
end)
```
