Ich habe hier einen Fehler in main.lua: 178: Versuch Index global 'pausebutton' (ein Null-Wert)

Question

Ich habe einen Fehler in Corona Simulator-Konsole in main.lua

Versuch Index global pausebutton (ein Nullwert)

Wie löst man mein Problem mit Corona-Fehler?

Die Revelant Code aus main.lua Datei-I unter

-- 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

habe ich glaube, Sie Fehler bekommen, weil lokale Variablen pausebutton und resumebutton nur existieren, während der pauseAndResume Funktion ausführt. Danach sind sie gegangen. Sie müssen sie also in dem Block deklarieren, in dem sie für die Funktionen pauseAndResume und pauseGame verfügbar sind, zum Beispiel am Anfang der Datei main.lua.

Versuchen

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 

Von Lua documentation

Wir schaffen lokale Variablen mit der lokalen Aussage:

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

Im Gegensatz zu globalen Variablen haben die lokalen Variablen ihren Umfang begrenzt die blockieren, wo sie deklariert sind. Ein Block ist der Rumpf einer Steuerelementstruktur, der Körper einer Funktion oder ein Chunk (die Datei oder Zeichenfolge mit der Code, in dem die Variable deklariert ist).

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 

lokale 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 

Funktion 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()