尝试索引全局“事件”（nil值）

我是lua的新手，并尝试查看具有类似错误的其他帖子。我无法解决我的问题。

我试图使我的数字对象在方向上使用alpha消失，并出现正确放置的对象。我添加了onOrientationLeft函数，并为其添加了一个侦听器。完成此操作后，我收到了我的错误，无法弄清楚如何使其正常工作。我的代码中的注释将说明我正在尝试执行的操作，请找到函数onOrientationLeft以及链接到它的最后一个运行时。

pZeroButton = display.newImage ("0.png",100, 470 )
llZeroButton = display.newImage ("0.png", 200,200)
llZeroButton.alpha = 0

pOneButton = display.newImage ("1.png",56,420)

pTwoButton = display.newImage ("2.png",123.5, 420)

pThreeButton = display.newImage ("3.png",191,420)

pFourButton = display.newImage ("4.png",56,370)

pFiveButton = display.newImage ("5.png",123.5, 370)

pSixButton = display.newImage ("6.png",191,370)

pSevenButton = display.newImage ("7.png",56,320 )

pEightButton = display.newImage ("8.png",123.5,320)

pNineButton = display.newImage ("9.png", 191, 320)



function onOrientationLeft ()
if (event.type == "landscapeRight") then
    print ("Test if this function onOrientationLeft is working properly") 
end
end 

-[[我已经添加了此函数，试图获取该函数以打印出字符串，但是每次我在电晕SDK模拟器中旋转手机时，都会出现尝试索引全局-'event'（nil值）的错误尝试- ]]

function calculateZero(number)
local pZeroButton = display.newText (0, 300,30,nil,38)
pZeroButton: setFillColor (0,0,0)
return
end



function calculateOne(number)
local pOneButton = display.newText (1, 300,30,nil,38)
pOneButton: setFillColor (0,0,0)
return
end

function calculateTwo(number)
local pTwoButton = display.newText (2, 300,30,nil,38)
pTwoButton: setFillColor (0,0,0)
return
end

function calculateThree(number)
local pThreeButton = display.newText (3, 300,30,nil,38)
pThreeButton: setFillColor (0,0,0)
return
end

function calculateFour(number)
local pFourButton = display.newText (4, 300,30,nil,38)
pFourButton: setFillColor (0,0,0)
return
end

function calculateFive(number)
local pFiveButton = display.newText (5, 300,30,nil,38)
pFiveButton: setFillColor (0,0,0)
return
end

function calculateSix(number)
local pSixButton = display.newText (6, 300,30,nil,38)
pSixButton: setFillColor (0,0,0)
return
end

function calculateSeven(number)
local pSevenButton = display.newText (7, 300,30,nil,38)
pSevenButton: setFillColor (0,0,0)
return
end

function calculateEight(number)
local pEightButton = display.newText (8, 300,30,nil,38)
pEightButton: setFillColor (0,0,0)
return
end

function calculateNine(number)
local pNineButton = display.newText (9, 300,30,nil,38)
pNineButton: setFillColor (0,0,0) 
return
end



pZeroButton : addEventListener ("tap", calculateZero)

pOneButton : addEventListener ("tap", calculateOne)

pTwoButton : addEventListener ("tap", calculateTwo)

pThreeButton : addEventListener ("tap", calculateThree)

pFourButton : addEventListener ("tap", calculateFour)

pFiveButton : addEventListener ("tap", calculateFive)

pSixButton : addEventListener ("tap", calculateSix)

pSevenButton : addEventListener ("tap", calculateSeven)

pEightButton : addEventListener ("tap", calculateEight)

pNineButton : addEventListener ("tap", calculateNine)


Runtime : addEventListener ("orientation", onOrientationLeft)