給多個SKNode隨機生成SKTexture給出相同的輸出

Question

我使用下面的代碼來生成一個隨機的SKTexture並將它分配給一個SKSpriteNode。

var spriteTexture = [(SKTexture, String)]() 

     spriteTexture.append((SKTexture(imageNamed: "red"), "red")) 
     spriteTexture.append((SKTexture(imageNamed: "blue"), "blue")) 
     spriteTexture.append((SKTexture(imageNamed: "green"), "green")) 

let rand = Int(arc4random_uniform(UInt32(spriteTexture.count))) 
     let chosenSprite = spriteTexture[rand].0 as SKTexture 
     let spriteName = spriteTexture[rand].1 
     let spriteSkin = chosenSprite 

我使用此代碼將SKTexture分配給SKSpriteNode。

let Sprite1 = SKSpriteNode(texture: spriteSkin) 
let Sprite2 = SKSpriteNode(texture: spriteSkin) 

該代碼工作正常，並始終生成隨機圖像...但是，Sprite1和Sprite2總是具有相同的隨機圖像！

如何確保每個SKSpriteNode都有自己的「隨機」圖像？

感謝：d

Answer 1

你的皮膚是平等的，因爲你只有一個隨機數。

func getRandomSkin() -> SKTexture { 
    let rand = Int(arc4random_uniform(UInt32(spriteTexture.count))) 
    let chosenSprite = spriteTexture[rand].0 as SKTexture 
    return chosenSprite 
} 

let randomSkin1 = getRandomSkin() 
let randomSkin2 = getRandomSkin() 

let sprite1 = SKSpriteNode(texture: randomSkin1) 
let sprite2 = SKSpriteNode(texture: randomSkin2) 

UPDATE 如果你想要的名字：

func getRandomSkinNode() -> SKSpriteNode { 
    let rand = Int(arc4random_uniform(UInt32(spriteTexture.count))) 
    let chosenSprite = spriteTexture[rand].0 as SKTexture 
    let spriteName = spriteTexture[rand].1 
    let spriteNode = SKSpriteNode(texture: chosenSprite) 
    spriteNode.name = spriteName 
    return spriteNode 
} 

let sprite1 = getRandomSkinNode() 
let sprite2 = getRandomSkinNode() 

Answer 2

記住這是iOS中（而不是隻在iOS版）是態度不好給大寫你的屬性。

你可以簡單地做：

let rand = randomNumber(0...(spriteTexture.count-1)) 
let chosenSprite = spriteTexture[rand].0 as SKTexture 
let spriteName = spriteTexture[rand].1 
let spriteSkin = chosenSprite 
... 
let sprite1 = SKSpriteNode() 
if let skin = spriteSkin { 
    sprite1.texture = spriteSkin 
} 

func randomNumber(range: Range<Int> = 1...6) -> Int { 
    let min = range.startIndex 
    let max = range.endIndex 
    return Int(arc4random_uniform(UInt32(1 + max - min))) + min 
} 

根據您的意見：

把你的精靈在一個陣列通過使全局變量：

var spritesArray : [SKSpriteNode]! 

然後填充您的陣列並啓動scheduleTimer（在本例中爲每10秒啓動一次）：

... 
spritesArray = [sprites1,sprites2] 
var changeTxtTimer = NSTimer.scheduledTimerWithTimeInterval(10.0, target: self, selector: Selector("changeTxt"), userInfo: nil, repeats: true) 

func changeTxt() { 
    print("change textures...") 
    for sprite in spritesArray { 
     let rand = randomNumber(0...(spriteTexture.count-1)) 
     let chosenSprite = spriteTexture[rand].0 as SKTexture 
     let spriteName = spriteTexture[rand].1 
     sprite.texture = chosenSprite 
     sprite.name = spriteName 
    } 
}