Swift Sprite-kit：如何随机设置动画？

Question

    var lightTexture = SKTexture(imageNamed: "green light.png")
    var lightTexture2 = SKTexture(imageNamed: "red light.png")

    var animationLight = SKAction.animateWithTextures([lightTexture, lightTexture2], timePerFrame:     3)
    var changeLight = SKAction.repeatActionForever(animationLight)

    light = SKSpriteNode(texture: lightTexture)
    light.position = CGPointMake(CGRectGetMidX(self.frame), 650)
    light.runAction(changeLight)

    self.addChild(light)

I want to make the animation to be set at a random time interval (random time between 1 second and 3 seconds). Then, if the screen is touched when the red light is up, I want a game over sign to appear. Thank You in advance.

Answer 1

What you need to use is SKAction.waitForDuration(_:withRange:)

https://developer.apple.com/library/prerelease/ios/documentation/SpriteKit/Reference/SKAction_Ref/index.html#//apple_ref/occ/clm/SKAction/waitForDuration:withRange :

Or more specifically:

let lightTexture = SKTexture(imageNamed: "green light.png")
let lightTexture2 = SKTexture(imageNamed: "red light.png")

let animateLights = SKAction.sequence([
    SKAction.waitForDuration(2.0, withRange: 2.0),
    SKAction.animateWithTextures([lightTexture, lightTexture2], timePerFrame: 3)
    ])

let changeLight = SKAction.repeatActionForever(animateLights)

let light = SKSpriteNode(texture: lightTexture)
light.position = CGPointMake(400, 650)
light.runAction(changeLight)

self.addChild(light)

According to the documentation, your animation will last 2 seconds +/- 1 second.

Also note that I took the liberty of changing your "var" variables to "let" constants, because they are not being changed.