编码 SpriteKit 游戏，我收到 "Instance member 'minX' cannot be used on type 'CGRect"

Question

我无法通过 CGRect.minX/Y 和 CGRect.MaxX/Y 修复此错误消息。 "Instance member 'minX' cannot be used on type 'CGRect" 是错误。我能做些什么来解决它？

func spawnNewDisc(){

    var randomImageNumber = arc4random()%4
    randomImageNumber += 1

    let CheeseBlock = SKSpriteNode(imageNamed: "CheeseBlock\(randomImageNumber)")
    CheeseBlock.zPosition = 2
    CheeseBlock.name = "CheeseObject"

    let randomX = random(min: CGRect.minX(gameArea) + CheeseBlock.size.width/2,
                         max: CGRect.maxX(gameArea) - CheeseBlock.size.width/2)

    let randomY = random(min: CGRect.minY(gameArea) + CheeseBlock.size.height/2,
                         max: CGRect.maxY(gameArea) - CheeseBlock.size.height/2)

    CheeseBlock.position = CGPoint(x: randomX, y: randomY)
    self.addChild(CheeseBlock)

}

Answer 1

minX、maxX 等是实例属性，这意味着它们需要在 CGRect 实例上调用，而不是类型本身。

改变

CGRect.minX(gameArea)

到

gameArea.minX

旁注：在Swift（以及其他语言）中理解类型和实例之间的区别很重要。在 Swift 中，惯例是以大写字母开头的命名类型和以小写字母开头的实例。

你的代码行

let CheeseBlock = SKSpriteNode(imageNamed: "CheeseBlock\(randomImageNumber)")

应该改为

let cheeseBlock = SKSpriteNode(imageNamed: "CheeseBlock\(randomImageNumber)")

这样可以更轻松地分辨哪些变量是类型，哪些是实例。

编码 SpriteKit 游戏，我收到 "Instance member 'minX' cannot be used on type 'CGRect"

Coding SpriteKit game and I am receiving "Instance member 'minX' cannot be used on type 'CGRect"

swift

sprite-kit

cgrect

cgfloat