我正在使用电晕样本代码中包含的功能进行缩放。但是因为我正在开发一个应用程序,我需要让每个感兴趣的地方都可以进行缩放。我是否必须为每个图像复制并粘贴可怕的长函数,或者我可以仅在一个函数上重定向每个图像?我是lua的新手,这里是示例代码中包含的缩放缩放功能:
function background:touch( event )
local result = true
local phase = event.phase
local previousTouches = self.previousTouches
local numTotalTouches = 1
if ( previousTouches ) then
-- add in total from previousTouches, subtract one if event is already in the array
numTotalTouches = numTotalTouches + self.numPreviousTouches
if previousTouches[event.id] then
numTotalTouches = numTotalTouches - 1
end
end
if "began" == phase then
-- Very first "began" event
if ( not self.isFocus ) then
-- Subsequent touch events will target button even if they are outside the contentBounds of button
display.getCurrentStage():setFocus( self )
self.isFocus = true
previousTouches = {}
self.previousTouches = previousTouches
self.numPreviousTouches = 0
elseif ( not self.distance ) then
local dx,dy
if previousTouches and ( numTotalTouches ) >= 2 then
dx,dy = calculateDelta( previousTouches, event )
end
-- initialize to distance between two touches
if ( dx and dy ) then
local d = math.sqrt( dx*dx + dy*dy )
if ( d > 0 ) then
self.distance = d
self.xScaleOriginal = self.xScale
self.yScaleOriginal = self.yScale
print( "distance = " .. self.distance )
end
end
end
if not previousTouches[event.id] then
self.numPreviousTouches = self.numPreviousTouches + 1
end
previousTouches[event.id] = event
elseif self.isFocus then
if "moved" == phase then
if ( self.distance ) then
local dx,dy
if previousTouches and ( numTotalTouches ) >= 2 then
dx,dy = calculateDelta( previousTouches, event )
end
if ( dx and dy ) then
local newDistance = math.sqrt( dx*dx + dy*dy )
local scale = newDistance / self.distance
print( "newDistance(" ..newDistance .. ") / distance(" .. self.distance .. ") = scale(".. scale ..")" )
if ( scale > 0 ) then
self.xScale = self.xScaleOriginal * scale
self.yScale = self.yScaleOriginal * scale
end
end
end
if not previousTouches[event.id] then
self.numPreviousTouches = self.numPreviousTouches + 1
end
previousTouches[event.id] = event
elseif "ended" == phase or "cancelled" == phase then
if previousTouches[event.id] then
self.numPreviousTouches = self.numPreviousTouches - 1
previousTouches[event.id] = nil
end
if ( #previousTouches > 0 ) then
-- must be at least 2 touches remaining to pinch/zoom
self.distance = nil
else
-- previousTouches is empty so no more fingers are touching the screen
-- Allow touch events to be sent normally to the objects they "hit"
display.getCurrentStage():setFocus( nil )
self.isFocus = false
self.distance = nil
self.xScaleOriginal = nil
self.yScaleOriginal = nil
-- reset array
self.previousTouches = nil
self.numPreviousTouches = nil
end
end
end
return result
端
答案 0 :(得分:0)
假设您的所有兴趣点都相似,您可以使用closure来完成此任务。
示例:
local function createPOI(properties)
local pointOfInterest = createPointOfInterest() -- code to create your object
--set properties based on argument
function pointOfInterest:touch(e)
--do stuff
end
pointOfInterest:addEventListner("touch")
return pointOfInterest
end
Corona有一些可能有用的代码here。检查“多次触摸”'部分。