检查图像是否可见（CoronaSDK）

Question

我是新来的coronaSDK，现在我面临一个问题。我只是想知道如何检查图像是否可见。

local function buttonListener1(event) 
    local lockedImage = display.newImage("locked.png") 
    lockedImage.x = 240 
    lockedImage.y = 170 
    lockedImage.isVisible = true 
    local myClosure = function() lockedImage.isVisible = false end 
    timer.performWithDelay(1000,myClosure) 
end 

我想要做的是首先要检查是否lockedImage可见或不可见。如果true那么lockedImage一旦触发就不会再次出现。否则，它会出现并执行timer.performWithDelay(1000,myClosure)。任何帮助真诚赞赏。对不起我的英语不好。提前致谢！

Answer 1

如何：

if myImage.isVisible then 
    ... do something ... 
end 

但要做到你描述的lockedImage必须buttonListener1之外创建的，因此上述技术意味着类似：

local lockedImage = display.newImage("locked.png") 
lockedImage.x = 240 
lockedImage.y = 170 
lockedImage.isVisible = false 
lockedImage:addEventListener... 

... presumably some listener might toggle lockedImage.isVisible 
    to true at some point ... 

-- some button listener: 
local function buttonListener1(event) 
    if lockedImage.isVisible == false then 
     -- show for one second 
     lockedImage.isVisible = true 
     local myClosure = function() lockedImage.isVisible = false end 
     timer.performWithDelay(1000, myClosure) 
    end 
end