生成随机颜色并将其分配给对象

Question

I want to make Obstacle_Color = random color instead of blackcolor . I found random color implementation but couldn't merge `Obstacle_Color with the return val of rand method. Thanks in advance!

import Foundation
import SpriteKit

class AKObstacle: SKSpriteNode {

    let Obstacle_Width: CGFloat = 40.0
    let Obstacle_Height: CGFloat = 70.0
    let Obstacle_Color = UIColor.blackColor()

    init(){

        let size = CGSizeMake(Obstacle_Width, Obstacle_Height)
        super.init(texture: nil, color: Obstacle_Color, size: size)

        loadPhysicsBoadyWithSize(size)
        startMoving()

    }

---

func getRandomColor() -> UIColor{

    var randomRed:CGFloat = CGFloat(drand48())

    var randomGreen:CGFloat = CGFloat(drand48())

    var randomBlue:CGFloat = CGFloat(drand48())

    return UIColor(red: randomRed, green: randomGreen, blue: randomBlue, alpha: 1.0)

}

Answer 1

One solution would be to make get randomcolor a static function and call it as a class method. Another one (probably better, since that function doesn't seem to be specifically linked to that class) is to make it a public method. Also someone else suggested to call it in the constructor, which also works.

Solution 1

import UIKit
import Foundation
import SpriteKit

class AKObstacle: SKSpriteNode {

    let Obstacle_Width: CGFloat = 40.0
    let Obstacle_Height: CGFloat = 70.0
    let Obstacle_Color = AKObstacle.getRandomColor()

    init() { ... }

    static func getRandomColor() -> UIColor {

        var randomRed:CGFloat = CGFloat(drand48())

        var randomGreen:CGFloat = CGFloat(drand48())

        var randomBlue:CGFloat = CGFloat(drand48())

        return UIColor(red: randomRed, green: randomGreen, blue: randomBlue, alpha: 1.0)
    }
}

Solution 2

import UIKit
import Foundation
import SpriteKit

class AKObstacle: SKSpriteNode {

    let Obstacle_Width: CGFloat = 40.0
    let Obstacle_Height: CGFloat = 70.0
    let Obstacle_Color = getRandomColor()

    init() {...}

}

public func getRandomColor() -> UIColor {

    var randomRed:CGFloat = CGFloat(drand48())

    var randomGreen:CGFloat = CGFloat(drand48())

    var randomBlue:CGFloat = CGFloat(drand48())

    return UIColor(red: randomRed, green: randomGreen, blue: randomBlue, alpha: 1.0)
}

Answer 2

你可以说

super.init(texture: nil, color: getRandomColor(), size: size)

Answer 3

You can't use self before super.init call. You can implement an extension of UIColor class

class MyClass: SKSpriteNode {

    let Obstacle_Width: CGFloat = 40.0
    let Obstacle_Height: CGFloat = 70.0

    init(){

        let size = CGSizeMake(Obstacle_Width, Obstacle_Height)

        super.init(texture: nil, color: UIColor.Obstacle_Color(), size: size)

    }
}

extension UIColor{

    class func Obstacle_Color() -> UIColor {

        var randomRed:CGFloat = CGFloat(drand48())

        var randomGreen:CGFloat = CGFloat(drand48())

        var randomBlue:CGFloat = CGFloat(drand48())

        return UIColor(red: randomRed, green: randomGreen, blue: randomBlue, alpha: 1.0)
    }
}