问题
hey guys i am about to finish my game i am a indie developer and i i am trying to finish my app in corona sdk and i keep getting this annoying error message. The message is get is "Attempt to compare nil with number restart.lua 9 " i don't have a clue how to fix this i try every thing but nothing works. when i run my code and i die for the first time and restart the game it work fine but the second time the player die ,and i try to restart the game i get this error message. this is the code
okay i want to be clear about this so i am going to post my hole code in the game 2 file so you guys can understand what i am going at.
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-- main.lua
---local titlebar = "no title bar"
-- requirs physics
--variable to hold our game's score
local score = 0
local physics = require "physics"
physics.start()
require "sprite"
local storyboard = require("storyboard")
local scene = storyboard.newScene()
function scene:createScene(event)
local screenGroup = self.view
-- background
local background = display.newImage("background01.png")
screenGroup:insert(background)
-- local background = display.newImageRect( "background01.png", 570, 360 )
--ship =display.newImage("empire 2.png")
top1 = display.newImage("invisable tile.png")
top1:setReferencePoint(display.BottomLeftReferencePoint)
top1.x=0
top1.y= -200
physics.addBody(top1, "static", {density=.1,bounce=0.1, friction=.2})
screenGroup:insert(top1)
top2 = display.newImage("invisable tile.png")
top2:setReferencePoint(display.BottomLeftReferencePoint)
top2.x =0
top2.y= 400
physics.addBody(top2, "static", {density=.1,bounce=0.1, friction=.2})
screenGroup:insert(top2)
moon = display.newImage("moon.png")
moon:setReferencePoint(display.BottomLeftReferencePoint)
moon.x =400
moon.y=100
moon.speed = 4
screenGroup:insert(moon)
moon2 = display.newImage("moon.png")
moon2: setReferencePoint(display.BottomLeftReferencePoint)
moon2.x =1090
moon2.y=100
moon2.speed = 4
screenGroup:insert(moon2)
-- this copy to the next scroll secne --empire should be change varable
empire3 = display.newImage("empire1.png")
empire3: setReferencePoint(display.BottomLeftReferencePoint)
empire3.x =1400
empire3.y=450
empire3.speed = 7
screenGroup:insert(empire3)
-- local empire2 = display.newImage("empire 2.png")
-- empire2: setReferencePoint(display.BottomLeftReferencePoint)
-- empire2.x = 400
-- empire2.y= 400
-- empire2.speed = 10
-- local empire4 = display.newImage("empire 2.png") -- copy of empire 2
-- empire4: setReferencePoint(display.BottomLeftReferencePoint)
--empire4.x = 1090
-- empire4.y= 400
-- empire4.speed = 10
-- this copy to the next scroll secne
empire1 =display.newImage("empire1.png")
empire1: setReferencePoint(display.BottomLeftReferencePoint)
empire1.x =570
empire1.y= 450
empire1.speed = 7
screenGroup:insert(empire1)
jetSpriteSheet = sprite.newSpriteSheet("jet11.png",50,17)
jetSprites = sprite.newSpriteSet(jetSpriteSheet,1,4)
sprite.add(jetSprites,"jets",1,4,5000,0)-- timer
jet=sprite.newSprite(jetSprites)
jet.y = 40
jet.x = -80
jet:prepare("jets")
jet.collided = false
jet:play()
physics.addBody(jet, "static", {density=.1,bounce=0.1, friction=.2,radius=12})
screenGroup:insert(jet)
jetIntro = transition.to(jet,{time=6000, x=100, onComplete=jetReady})
explosionSpriteSheet = sprite.newSpriteSheet("explosion.png", 24, 23)
explosionSprites = sprite.newSpriteSet(explosionSpriteSheet, 1, 8)
sprite.add(explosionSprites, "explosions", 1, 8, 2000, 1)
explosion = sprite.newSprite(explosionSprites)
explosion.x = 100
explosion.y = 100
explosion:prepare("explosions")
explosion:play()
explosion.isVisible = false
-- physics.addBody(jet, "dynamic", {density=.1, bounce=0.1, friction=.2, radius=12})
screenGroup:insert(explosion)
mine1 = display.newImage("rocket01.png")
mine1.x = 500
mine1.y = 200
mine1.speed = math.random(2,6)
-- mine1.initY = mine1.y
-- mine1.amp = math.random(20,100)
-- mine1.angle = math.random(1,360)
physics.addBody(mine1, "static", {density=.1, bounce=0.1, friction=.2, radius=12})
screenGroup:insert(mine1)
mine2 = display.newImage("missles.png")
mine2.y = 100--math.random (1,100)
mine2.x = 1090
mine2.speed = math.random(2,6)
-- mine2.amp = math.random(2,6)
--mine2.initY = mine2.y
physics.addBody(mine2, "static", {density=.1,bounce=0.1, friction=.2,radius=12})
screenGroup:insert(mine2)
mine3 = display.newImage("missles.png")
mine3.y = 100
mine3.x = 500
mine3.speed = math.random(2,6)
-- mine3.initY = mine1.y
-- mine3.amp = math.random(20,100)
mine3.angle = math.random(1,360)
physics.addBody(mine3, "static", {density=.1,bounce=0.1, friction=.2,radius=12})
screenGroup:insert(mine3)
mine4 = display.newImage("rocket01.png")
mine4.y = 100
mine4.x = 500
mine4.speed = math.random(2,6)
-- mine3.initY = mine1.y
-- mine3.amp = math.random(20,100)
mine3.angle = math.random(1,360)
screenGroup:insert(mine4)
physics.addBody(mine4, "static", {density=.1,bounce=0.1, friction=.2,radius=12})
screenGroup:insert(mine4)
coin04 = display.newImage("coin04.png")
coin04.y = 100
coin04.x = 500
coin04.speed = math.random(2,6)
coin04.initY = mine1.y
coin04.amp = math.random(20,100)
coin04.angle = math.random(1,360)
physics.addBody(coin04, "static", {density=.1,bounce=0.1, friction=.2,radius=12})
screenGroup:insert(coin04)
rocket02 = display.newImage("rocket02.png")
rocket02.y = 100
rocket02.x = 500
rocket02.speed = math.random(2,6)
rocket02.initY = mine1.y
rocket02.amp = math.random(20,100)
rocket02.angle = math.random(1,360)
physics.addBody(rocket02, "static", {density=.1,bounce=0.1, friction=.2,radius=12})
screenGroup:insert(rocket02)
rocket03 = display.newImage("rocket02.png")
rocket03.y = 100
rocket03.x = 500
rocket03.speed = math.random(2,6)
rocket03.initY = mine1.y
rocket03.amp = math.random(20,100)
rocket03.angle = math.random(1,360)
physics.addBody(rocket03, "static", {density=.1,bounce=0.1, friction=.2,radius=12})
screenGroup:insert(rocket03)
rocket04 = display.newImage("rocket02.png")
rocket04.y = 100
rocket04.x = 500
rocket04.speed = math.random(2,6)
rocket04.initY = mine1.y
rocket04.amp = math.random(20,100)
rocket04.angle = math.random(1,360)
physics.addBody(rocket04, "static", {density=.1,bounce=0.1, friction=.2,radius=12})
screenGroup:insert(rocket04)
ball01 = display.newImage("ball01.png")
ball01.y = 100
ball01.x = 500
ball01.speed = math.random(2,6)
ball01.initY = mine1.y
ball01.amp = math.random(20,100)
ball01.angle = math.random(1,360)
rotation = 2
physics.addBody(ball01, "static", {density=.1,bounce=0.1, friction=.2,radius=12})
screenGroup:insert(ball01)
ball02 = display.newImage("ball01.png")
ball02.y = 100
ball02.x = 500
ball02.speed = math.random(2,6)
ball02.initY = mine1.y
ball02.amp = math.random(20,100)
ball02.angle = math.random(1,360)
rotation = 2
physics.addBody(ball02, "static", {density=.1,bounce=0.1, friction=.2,radius=12})
screenGroup:insert(ball02)
ball03 = display.newImage("ball02.png")
ball03.y = 100
ball03.x = 500
ball03.speed = math.random(2,6)
--ball03.initY = mine1.y
-- ball03.amp = math.random(20,100)
ball03.angle = math.random(1,360)
rotation = 2
physics.addBody(ball03, "static", {density=.1,bounce=0.1, friction=.2,radius=12})
screenGroup:insert(ball03)
ball04 = display.newImage("ball02.png")
ball04.y = 100
ball04.x = 500
ball04.speed = math.random(2,6)
ball04.initY = mine1.y
ball04.amp = math.random(20,100)
ball04.angle = math.random(1,360)
rotation = 2
physics.addBody(ball04, "static", {density=.1,bounce=0.1, friction=.2,radius=12})
screenGroup:insert(ball04)
coin01 = display.newImage("coin02.png")
coin01.y = 100
coin01.x = 500
coin01.speed = math.random(2,6)
coin01.initY = mine1.y
coin01.amp = math.random(20,100)
coin01.angle = math.random(1,360)
physics.addBody(coin01, "static", {density=.1,bounce=0.1, friction=.2,radius=12})
screenGroup:insert(coin01)
scoreText = display.newText("score: " .. score, 0, 0, "showcardgothic", 14)
scoreText:setTextColor(225,225,225)
scoreText.x = 10
scoreText.y = 20
screenGroup:insert(scoreText)
pause = display.newImage("pause.png")
pause.x = 480
pause.y = 289
screenGroup:insert(pause)
end -- end of create scene
local function scoreUpdate()
score =score +10
scoreText.text = "score:"..score
---scoreText:setTextColor(225,225,225)
-- scoreText:setReferencePoint(display.CenterLeftReferencePoint)
scoreText.x = 10
scoreText.y =20
end
timer1 = timer.performWithDelay( 1000, scoreUpdate, - 1 )
function pause01 (event)
if event.phase =="began" then
--print "hi"
function jetReady()
jet.bodyType = "static"
end
storyboard.gotoScene("pause menu","crossFade",400)
result = timer.pause( timer1 )
print( "Time remaining is ")
end
end
this code that is below that is bold is the code that's giving problem hope you guys can tell me whats wrong..
***print "passed"***
***function scrollSpace(self,event)
if self.x < -900 then
self.x = 800
else
self.x = self.x - self.speed
end
end***
local function moveMines(self,event)
if self.x < -900 then
self.x = 489 --800
self.y = math.random(90,220)
self.x = 500
self.speed = math.random(2,6)
-- self.amp = math.random(20,100)
-- self.angle = math.random(1,360)
else
self.x = self.x - self.speed
-- self.angle = self.angle + .1
-- self.y = self.amp * math.sin(self.angle)+ self.initY
end
end
local function coins(self,event)
if self.x < -900 then
self.x = 800
self.y = math.random(90,100)
self.x = 500
self.speed = math.random(2,6)
self.amp = math.random(20,100)
self.angle = math.random(1,360)
else
self.x = self.x - self.speed
self.angle = self.angle + .1
self.y = self.amp * math.sin(self.angle)+ self.initY
end
end
-- moveMissile1
function jetReady()
jet.bodyType = "dynamic"
end
function activateJets(self,event)
self:applyForce(0,-1.5,self.x,self.y)
end
function touchScreen(event)
--print("touch")
if event.phase == "began"then
jet.enterFrame = activateJets
Runtime:addEventListener ("enterFrame",jet)
end
if event.phase == "ended"then
--print ("ended")
Runtime:removeEventListener ("enterFrame",jet)
end
end
function gameOver()
storyboard.gotoScene("restart", "fade", 400)
end
function explode()
explosion.x = jet.x
explosion.y = jet.y
explosion.isVisible = true
explosion:play()
jet.isVisible = false
timer.performWithDelay(3000, gameOver, 1)
end
function onCollision(event)
if event.phase == "began" then
if jet.collided == false then
jet.collided = true
jet.bodyType = "static"
result = timer.pause(timer1 )
explode()
--storyboard.gotoScene("restart", "fade", 400)
end
end
end
function scene:enterScene(event)
moon.enterFrame = scrollSpace
Runtime:addEventListener ("enterFrame",moon)
pause:addEventListener("touch",pause01)
empire3.enterFrame = scrollSpace
Runtime:addEventListener ("enterFrame",empire3)
moon2.enterFrame = scrollSpace
Runtime:addEventListener ("enterFrame",moon2)
mine1.enterFrame = moveMines
Runtime:addEventListener ("enterFrame",mine1)
mine2.enterFrame = moveMines
Runtime:addEventListener ("enterFrame",mine2)
mine3.enterFrame = moveMines
Runtime:addEventListener ("enterFrame",mine3)
mine4.enterFrame = moveMines
Runtime:addEventListener ("enterFrame",mine4)
rocket02 .enterFrame = coins
Runtime:addEventListener ("enterFrame",rocket02)
coin04.enterFrame = coins
Runtime:addEventListener ("enterFrame",coin04)
coin01.enterFrame = coins
Runtime:addEventListener ("enterFrame",coin01)
rocket03 .enterFrame = coins
Runtime:addEventListener ("enterFrame",rocket03)
rocket04 .enterFrame = moveMines
Runtime:addEventListener ("enterFrame",rocket04)
ball01 .enterFrame = coins
Runtime:addEventListener ("enterFrame",ball01)
ball02 .enterFrame = coins
Runtime:addEventListener ("enterFrame",ball02)
ball03 .enterFrame = moveMines
Runtime:addEventListener ("enterFrame",ball03)
ball04 .enterFrame = coins
Runtime:addEventListener ("enterFrame",ball04)
-- empire2.enterFrame = scrollSpace
--Runtime:addEventListener ("enterFrame",empire2)
-- empire4.enterFrame = scrollSpace
-- Runtime:addEventListener ("enterFrame",empire4)
empire1.enterFrame = scrollSpace
Runtime:addEventListener ("enterFrame",empire1)
Runtime:addEventListener("touch",touchScreen)
Runtime:addEventListener("collision",onCollision)
end
function scene:exitScene(event)
Runtime:removeEventListener("touch",touchScreen)
Runtime:removeEventListener ("enterFrame",moon)
Runtime:removeEventListener ("enterFrame",empire3)
Runtime:removeEventListener ("enterFrame",moon2)
Runtime:removeEventListener ("enterFrame",mine1)
Runtime:removeEventListener ("enterFrame",mine2)
Runtime:removeEventListener ("enterFrame",mine3)
Runtime:removeEventListener ("enterFrame",mine4)
Runtime:removeEventListener ("enterFrame",coin04)
Runtime:removeEventListener ("enterFrame",coin01)
Runtime:removeEventListener ("enterFrame",empire1)
Runtime:removeEventListener("collision",onCollision)
Runtime: removeEventListener ("enterFrame",rocket02)
end
function scene:destroyScene(event)
end
scene:addEventListener("createScene",scene)
scene:addEventListener("enterScene",scene)
scene:addEventListener("exitScene",scene)
scene:addEventListener("destroyScene",scene)
return scene
回答1:
Apparently, self.x doesn't exist. Make sure that you initialize it somewhere before that compare at line 9. I think you are lucky, these kinds of bugs are usually solved easily..
If you still can't figure it out, post where you first initialize self.x, could be something you are missing.
来源：https://stackoverflow.com/questions/17625414/attempt-to-compare-nil-with-number-in-game