я получил ошибку здесь в main.lua: 178: попытка индекса глобальной «pausebutton» (нилъ значения)

Question

я получил ошибку в тренажере консоли Corona в main.lua

попытки индексировать глобальный pausebutton (значение nil)

Как решить мою проблему с ошибкой Corona?

Самый revelant код из файла main.lua я ставлю ниже

-- Display the pause button 
function pauseAndResume() 
    local pausebutton = display.newImage ("pause.png") 
    pausebutton : translate(100, 100) 
    pausebutton:addEventListener ("touch" , pauseGame) 

    local resumebutton = display.newImage ("resumed.png") 
    resumebutton: translate(100, 100) 
    resumebutton.isVisible = false 
    resumebutton:addEventListener ("touch", resumeGame) 
end 

function pauseGame (event) 
    if (event.phase == "ended") then 
     physics.pause() 
     pausebutton.isVisible = false 
     resumebutton.isVisible = true 
     timer.pause(fruitTimer) 
     timer.pause(bombTimer) 
     sampleVar = false 
     return true 
    end 
end 

function resumeGame (event) 
    if (event.phase == "ended") then 
     physics.start() 
     pausebutton.isVisible = true 
     resumebutton.isVisible = false 
     timer.resume(fruitTimer) 
     timer.resume(bombTimer) 
     sampleVar = true 
     return true 
    end 
end 

Answer 1

Я думаю, что вы получили сообщение об ошибке, потому что локальные переменные pausebutton и resumebutton существуют только во время выполнения из pauseAndResume функции. После этого они ушли. Поэтому вам необходимо объявить их в блоке, в котором они будут доступны для функций pauseAndResume и pauseGame, например, при начале файла main.lua.

Попробуйте

local pausebutton 
local resumebutton 

... 

-- Display the pause button 
function pauseAndResume()  
    pausebutton = display.newImage ("pause.png") 
    pausebutton : translate(100, 100) 
    pausebutton:addEventListener ("touch" , pauseGame) 

    resumebutton = display.newImage ("resumed.png") 
    resumebutton: translate(100, 100) 
    resumebutton.isVisible = false 
    resumebutton:addEventListener ("touch", resumeGame) 
end 

function pauseGame (event) 
    if (event.phase == "ended") then 
     physics.pause() 
     pausebutton.isVisible = false 
     resumebutton.isVisible = true 
     timer.pause(fruitTimer) 
     timer.pause(bombTimer) 
     sampleVar = false 
     return true 
    end 
end 

function resumeGame (event) 
    if (event.phase == "ended") then 
     physics.start() 
     pausebutton.isVisible = true 
     resumebutton.isVisible = false 
     timer.resume(fruitTimer) 
     timer.resume(bombTimer) 
     sampleVar = true 
     return true 
    end 
end 

С Lua documentation

Мы создаем локальные переменные с местным утверждением:

j = 10   -- global variable 
local i = 1 -- local variable 

В отличие от глобальных переменных, локальные переменные их объем ограничивается в блок, где они объявлены. Блок представляет собой тело элемента управления структуры , тела функции или фрагмента (файла или строки с кодом, где объявлена ​​переменная).

Answer 2

- Samurai Fruit

require ("physics") 
local ui = require("ui") 

physics.start() 
-- physics.setDrawMode ("hybrid") -- Uncomment in order to show in hybrid mode  
physics.setGravity(0, 9.8 * 2) 

physics.start() 

-- Audio for slash sound (sound you hear when user swipes his/her finger across the screen) 
local slashSounds = {slash1 = audio.loadSound("slash1.wav"), slash2 = audio.loadSound("slash2.wav"), slash3 = audio.loadSound("slash3.wav")} 
local slashSoundEnabled = true -- sound should be enabled by default on startup 
local minTimeBetweenSlashes = 150 -- Minimum amount of time in between each slash sound 
local minDistanceForSlashSound = 50 -- Amount of pixels the users finger needs to travel in one frame in order to play a slash sound 

-- Audio for chopped fruit 
local choppedSound = {chopped1 = audio.loadSound("chopped1.wav"), chopped2 = audio.loadSound("chopped2.wav")} 

-- Audio for bomb 
local preExplosion = audio.loadSound("preExplosion.wav") 
local explosion = audio.loadSound("explosion.wav") 

-- Adding a collision filter so the fruits do not collide with each other, they only collide with the catch platform 
local fruitProp = {density = 1.0, friction = 0.3, bounce = 0.2, filter = {categoryBits = 2, maskBits = 1}} 
local catchPlatformProp = {density = 1.0, friction = 0.3, bounce = 0.2, filter = {categoryBits = 1, maskBits = 2}} 

-- Gush filter should not interact with other fruit or the catch platform 
local gushProp = {density = 1.0, friction = 0.3, bounce = 0.2, filter = {categoryBits = 4, maskBits = 8} } 

-- Will contain all fruits available in the game 

местного avalFruit = {}

-- Slash line properties (line that shows up when you move finger across the screen) 
local maxPoints = 5 
local lineThickness = 20 
local lineFadeTime = 250 
local endPoints = {} 

-- Whole Fruit physics properties 
local minVelocityY = 850 
local maxVelocityY = 1100 

local minVelocityX = -200 
local maxVelocityX = 200 

local minAngularVelocity = 100 
local maxAngularVelocity = 200 

-- Chopped fruit physics properties 
local minAngularVelocityChopped = 100 
local maxAngularVelocityChopped = 200 

-- Splash properties 
local splashFadeTime = 2500 
local splashFadeDelayTime = 5000 
local splashInitAlpha = .5 
local splashSlideDistance = 50 -- The amoutn of of distance the splash slides down the background 

-- Contains all the available splash images 
local splashImgs = {} 

-- Gush properties 
local minGushRadius = 10 
local maxGushRadius = 25 
local numOfGushParticles = 15 
local gushFadeTime = 500 
local gushFadeDelay = 500 

local minGushVelocityX = -350 
local maxGushVelocityX = 350 
local minGushVelocityY = -350 
local maxGushVelocityY = 350 

-- Timer references 
local bombTimer 
local fruitTimer 

-- Game properties 
local fruitShootingInterval = 1000 
local bombShootingInterval = 5000 

-- Groups for holding the fruit and splash objects 
local splashGroup 
local fruitGroup 

local sampleVar = true 
local score = 0 
local scoreText 


function main() 

    score = 0 
    display.setStatusBar(display.HiddenStatusBar) 

    setUpBackground() 

    scoreText = display.newText("Score: 0", 415, 100, native.systemFont, 50) 
    scoreText:setTextColor(255, 255, 255) 
    scoreText.text = ("Score: ")..score 

    pauseAndResume() 
    setUpCatchPlatform() 
    initGroups() 
    initFruitAndSplash() 


    Runtime:addEventListener("touch", drawSlashLine) 
    timer.performWithDelay(1000, displayScore) 
    startGame() 
end 

function displayScore() 

    scoreText.text = ("Score: ")..score 
    score = score + 2 


end 


function startGame() 

     shootObject("fruit") 

     bombTimer = timer.performWithDelay(bombShootingInterval, function(event) shootObject("bomb") end, 0) 
     fruitTimer = timer.performWithDelay(fruitShootingInterval, function(event) shootObject("fruit") end, 0) 

end 


-- Display the pause button 
function pauseAndResume() 

    local pausebutton = display.newImage ("pause.png") 
    pausebutton : translate(100, 100) 

    pausebutton:addEventListener ("touch" , pauseGame) 

    local resumebutton = display.newImage ("resumed.png") 

    resumebutton: translate(100, 100) 

    resumebutton.isVisible = false 

    resumebutton:addEventListener ("touch", resumeGame) 
end 

function pauseGame (event) 
    if (event.phase == "ended") then 
     physics.pause() 
     pausebutton.isVisible = false 
     resumebutton.isVisible = true 
     timer.pause(fruitTimer) 
     timer.pause(bombTimer) 
     sampleVar = false 
     return true 
    end 
end 

function resumeGame (event) 
    if (event.phase == "ended") then 
     physics.start() 
     pausebutton.isVisible = true 
     resumebutton.isVisible = false 
     timer.resume(fruitTimer) 
     timer.resume(bombTimer) 
     sampleVar = true 
     return true 
    end 
end 

function initGroups() 
    splashGroup = display.newGroup() 
    fruitGroup = display.newGroup() 
end 

function setUpBackground() 

    local background = display.newImage("bg.png", true) 
    background.x = display.contentWidth/2 
    background.y = display.contentHeight/2 

end 

-- Populates avalFruit with all the fruit images and thier widths and heights 
function initFruitAndSplash() 

    local watermelon = {} 
    watermelon.whole = "watermelonWhole.png" 
    watermelon.top = "watermelonTop.png" 
    watermelon.bottom = "watermelonBottom.png" 
    watermelon.splash = "redSplash.png" 
    table.insert(avalFruit, watermelon) 

    local strawberry = {} 
    strawberry.whole = "strawberryWhole.png" 
    strawberry.top = "strawberryTop.png" 
    strawberry.bottom = "strawberryBottom.png" 
    strawberry.splash = "redSplash.png" 
    table.insert(avalFruit, strawberry) 

    -- Initialize splash images 
    table.insert(splashImgs, "splash1.png") 
    table.insert(splashImgs, "splash2.png") 
    table.insert(splashImgs, "splash3.png") 
end 


function getRandomFruit() 

    local fruitProp = avalFruit[math.random(1, #avalFruit)] 
    local fruit = display.newImage(fruitProp.whole) 
    fruit.whole = fruitProp.whole 
    fruit.top = fruitProp.top 
    fruit.bottom = fruitProp.bottom 
    fruit.splash = fruitProp.splash 

    return fruit 

end 

function getBomb() 

    local bomb = display.newImage("bomb.png") 
    return bomb 
end 

function shootObject(type) 

    local object = type == "fruit" and getRandomFruit() or getBomb() 

    fruitGroup:insert(object) 

    object.x = display.contentWidth/2 
    object.y = display.contentHeight + object.height * 2 

    fruitProp.radius = object.height/2 
    physics.addBody(object, "dynamic", fruitProp) 

    if (type == "fruit") then 
     object:addEventListener("touch", function(event) chopFruit(object) end) 
    else 
     local bombTouchFunction 
     bombTouchFunction = function(event) explodeBomb(object, bombTouchFunction); end 
     object:addEventListener("touch", bombTouchFunction) 
    end 

    -- Apply linear velocity 
    local yVelocity = getRandomValue(minVelocityY, maxVelocityY) * -1 -- Need to multiply by -1 so the fruit shoots up 
    local xVelocity = getRandomValue(minVelocityX, maxVelocityX) 
    object:setLinearVelocity(xVelocity, yVelocity) 

    -- Apply angular velocity (the speed and direction the fruit rotates) 
    local minAngularVelocity = getRandomValue(minAngularVelocity, maxAngularVelocity) 
    local direction = (math.random() < .5) and -1 or 1 
    minAngularVelocity = minAngularVelocity * direction 
    object.angularVelocity = minAngularVelocity 

end 


function explodeBomb(bomb, listener) 

    bomb:removeEventListener("touch", listener) 

    -- The bomb should not move while exploding 
    bomb.bodyType = "kinematic" 
    bomb:setLinearVelocity(0, 0) 
    bomb.angularVelocity = 0 

    -- Shake the stage 
    local stage = display.getCurrentStage() 

    local moveRightFunction 
    local moveLeftFunction 
    local rightTrans 
    local leftTrans 
    local shakeTime = 50 
    local shakeRange = {min = 1, max = 25} 

    moveRightFunction = function(event) rightTrans = transition.to(stage, {x = math.random(shakeRange.min,shakeRange.max), y = math.random(shakeRange.min, shakeRange.max), time = shakeTime, onComplete=moveLeftFunction}); end 
    moveLeftFunction = function(event) leftTrans = transition.to(stage, {x = math.random(shakeRange.min,shakeRange.max) * -1, y = math.random(shakeRange.min,shakeRange.max) * -1, time = shakeTime, onComplete=moveRightFunction}); end 

    moveRightFunction() 

    local linesGroup = display.newGroup() 

    -- Generate a bunch of lines to simulate an explosion 
    local drawLine = function(event) 

     local line = display.newLine(bomb.x, bomb.y, display.contentWidth * 2, display.contentHeight * 2) 
     line.rotation = math.random(1,360) 
     line.strokeWidth = math.random(15, 25) 
     linesGroup:insert(line) 
    end 
    local lineTimer = timer.performWithDelay(100, drawLine, 0) 

    -- Function that is called after the pre explosion 
    local explode = function(event) 

     audio.play(explosion) 
     blankOutScreen(bomb, linesGroup); 
     timer.cancel(lineTimer) 
     stage.x = 0 
     stage.y = 0 
     transition.cancel(leftTrans) 
     transition.cancel(rightTrans) 

    end 

    -- Play the preExplosion sound first followed by the end explosion 
    audio.play(preExplosion, {onComplete = explode}) 

    timer.cancel(fruitTimer) 
    timer.cancel(bombTimer) 

end 

function blankOutScreen(bomb, linesGroup) 

    local gameOver = displayGameOver() 
    gameOver.alpha = 0 -- Will reveal the game over screen after the explosion 

    -- Create an explosion animation 
    local circle = display.newCircle(bomb.x, bomb.y, 5) 
    local circleGrowthTime = 300 
    local dissolveDuration = 1000 

    local dissolve = function(event) transition.to(circle, {alpha = 0, time = dissolveDuration, delay = 0, onComplete=function(event) gameOver.alpha = 1 end}); gameOver.alpha = 1 end 

    circle.alpha = 0 
    transition.to(circle, {time=circleGrowthTime, alpha = 1, strokeWidth = display.contentWidth * 3, height = display.contentWidth * 3, onComplete = dissolve}) 



end 

function displayGameOver() 

    -- Will return a group so that we can set the alpha of the entier menu 
    local group = display.newGroup() 

    -- Dim the background with a transperent square 
    -- local back = display.newRect(0,0, display.contentWidth, display.contentHeight) 
    --back:setFillColor(0,0,0, 255 * .1) 
    --group:insert(back) 

    local gameOver = display.newImage("gameover.png") 
    gameOver.x = display.contentWidth/2 
    gameOver.y = display.contentHeight/2 
    group:insert(gameOver) 

    local replayButton = ui.newButton{ 
     default = "replayButton.png", 
     over = "replayButton.png", 
     onRelease = function(event) group:removeSelf(); main() ; end 
    } 
    group:insert(replayButton) 



    replayButton.x = display.contentWidth/2 
    replayButton.y = gameOver.y + gameOver.height/2 + replayButton.height/2 


    return group 
end 

-- Return a random value between 'min' and 'max' 
function getRandomValue(min, max) 
    return min + math.abs(((max - min) * math.random())) 
end 

function playRandomSlashSound() 

    audio.play(slashSounds["slash" .. math.random(1, 3)]) 
end 

function playRandomChoppedSound() 

    audio.play(choppedSound["chopped" .. math.random(1, 2)]) 
end 

function getRandomSplash() 

    return display.newImage(splashImgs[math.random(1, #splashImgs)]) 
end 

function chopFruit(fruit) 

    if (sampleVar == true) then 


     displayScore() 
     playRandomChoppedSound() 


     createFruitPiece(fruit, "top") 
     createFruitPiece(fruit, "bottom") 

     createSplash(fruit) 
     createGush(fruit) 

     fruit:removeSelf() 


    end 


end 

-- Creates a gushing effect that makes it look like juice is flying out of the fruit 
function createGush(fruit) 

    local i 
    for i = 0, numOfGushParticles do 
     local gush = display.newCircle(fruit.x, fruit.y, math.random(minGushRadius, maxGushRadius)) 
    gush:setFillColor(255, 0, 0, 255) 

     gushProp.radius = gush.width/2 
     physics.addBody(gush, "dynamic", gushProp) 

     local xVelocity = math.random(minGushVelocityX, maxGushVelocityX) 
     local yVelocity = math.random(minGushVelocityY, maxGushVelocityY) 

     gush:setLinearVelocity(xVelocity, yVelocity) 

     transition.to(gush, {time = gushFadeTime, delay = gushFadeDelay, strokeWidth = 0, height = 0, alpha = 0, onComplete = function(event) gush:removeSelf() end})  
    end 

end 

function createSplash(fruit) 

    local splash = getRandomSplash() 
    splash.x = fruit.x 
    splash.y = fruit.y 
    splash.rotation = math.random(-90,90) 
    splash.alpha = splashInitAlpha 
    splashGroup:insert(splash) 

    transition.to(splash, {time = splashFadeTime, alpha = 0, y = splash.y + splashSlideDistance, delay = splashFadeDelayTime, onComplete = function(event) splash:removeSelf() end})  

end 

-- Chops the fruit in half 
-- Uses some trig to calculate the position 
-- of the top and bottom part of the chopped fruit (http://en.wikipedia.org/wiki/Rotation_matrix#Rotations_in_two_dimensions) 
function createFruitPiece(fruit, section) 

    local fruitVelX, fruitVelY = fruit:getLinearVelocity() 

    -- Calculate the position of the chopped piece 
    local half = display.newImage(fruit[section]) 
    half.x = fruit.x - fruit.x -- Need to have the fruit's position relative to the origin in order to use the rotation matrix 
    local yOffSet = section == "top" and -half.height/2 or half.height/2 
    half.y = fruit.y + yOffSet - fruit.y 

    local newPoint = {} 
    newPoint.x = half.x * math.cos(fruit.rotation * (math.pi/180)) - half.y * math.sin(fruit.rotation * (math.pi/180)) 
    newPoint.y = half.x * math.sin(fruit.rotation * (math.pi/180)) + half.y * math.cos(fruit.rotation * (math.pi/180)) 

    half.x = newPoint.x + fruit.x -- Put the fruit back in its original position after applying the rotation matrix 
    half.y = newPoint.y + fruit.y 
    fruitGroup:insert(half) 

    -- Set the rotation 
    half.rotation = fruit.rotation 
    fruitProp.radius = half.width/2 -- We won't use a custom shape since the chopped up fruit doesn't interact with the player 
    physics.addBody(half, "dynamic", fruitProp) 

    -- Set the linear velocity 
    local velocity = math.sqrt(math.pow(fruitVelX, 2) + math.pow(fruitVelY, 2)) 
    local xDirection = section == "top" and -1 or 1 
    local velocityX = math.cos((fruit.rotation + 90) * (math.pi/180)) * velocity * xDirection 
    local velocityY = math.sin((fruit.rotation + 90) * (math.pi/180)) * velocity 
    half:setLinearVelocity(velocityX, velocityY) 

    -- Calculate its angular velocity 
    local minAngularVelocity = getRandomValue(minAngularVelocityChopped, maxAngularVelocityChopped) 
    local direction = (math.random() < .5) and -1 or 1 
    half.angularVelocity = minAngularVelocity * direction 
end 

-- Creates a platform at the bottom of the game "catch" the fruit and remove it 

функция setUpCatchPlatform()

local platform = display.newRect(0, 0, display.contentWidth * 4, 50) 
    platform.x = (display.contentWidth/2) 
    platform.y = display.contentHeight + display.contentHeight 
    physics.addBody(platform, "static", catchPlatformProp) 

    platform.collision = onCatchPlatformCollision 
    platform:addEventListener("collision", platform) 
end 

function onCatchPlatformCollision(self, event) 
    -- Remove the fruit that collided with the platform 
    event.other:removeSelf() 
end 

-- Draws the slash line that appears when the user swipes his/her finger across the screen 
function drawSlashLine(event) 

    -- Play a slash sound 
    if(endPoints ~= nil and endPoints[1] ~= nil) then 
     local distance = math.sqrt(math.pow(event.x - endPoints[1].x, 2) + math.pow(event.y - endPoints[1].y, 2)) 
     if(distance > minDistanceForSlashSound and slashSoundEnabled == true) then 
     playRandomSlashSound(); 
      slashSoundEnabled = false 
      timer.performWithDelay(minTimeBetweenSlashes, function(event) slashSoundEnabled = true end) 
     end 
    end 

    -- Insert a new point into the front of the array 
    table.insert(endPoints, 1, {x = event.x, y = event.y, line= nil}) 

    -- Remove any excessed points 
    if(#endPoints > maxPoints) then 
     table.remove(endPoints) 
    end 

    for i,v in ipairs(endPoints) do 
     local line = display.newLine(v.x, v.y, event.x, event.y) 
     line.strokeWidth = lineThickness 
     transition.to(line, {time = lineFadeTime, alpha = 0, strokeWidth = 0, onComplete = function(event) line:removeSelf() end})   
    end 

    if(event.phase == "ended") then  
     while(#endPoints > 0) do 
      table.remove(endPoints) 
     end 
    end 
end 


main()