SKSpriteNode子类化swift [英] SKSpriteNode subclassing swift

问题描述

我已经找到了一些帖子，但我仍然对如何做到这一点感到困惑。我知道我必须使用指定的初始化程序，它是init（纹理：SKTexture！，颜色：UIColor！，大小：CGSize）。真的，我还是不会用它。我想只为sprite节点添加一些属性。

I have found a few posts on this but I'm still confused on how to do this. I know I have to use the "designated initializer" which is the init(texture: SKTexture!, color: UIColor!, size: CGSize). Really I won't use that anyway. I'd like to just add some properties to the sprite nodes.

class Piece: SKSpriteNode {

enum Type: Int {
    case type1 = 1, type2, type3, type4, type5
}

    var piecetype : Type 

init(texture: SKTexture!, color: UIColor!, size: CGSize)
{
    self.piecetype = .type1
    super.init(texture: texture, color: color, size: size)

}


convenience init(imageNamed: String!, currentPiece: Type)
    {
        self.piecetype = currentPiece
        let color = UIColor()
        let texture = SKTexture(imageNamed: imageNamed)
        let size = CGSizeMake(100.0, 100.0)
        super.init(texture: texture, color: color, size: size)
    }

主要代码中的

我尝试使用

in the main code I try to add a piece by using

var newPiece : Piece = Piece(imageNamed: "image.png", currentPiece: .type1)
self.addChild(newPiece)

好像我很接近，但我对如何做初始化器有点困惑。

It seems like I'm close, but I'm a bit confused on how to do the initializers.

推荐答案

只需将便利初始化程序更改为：

convenience init(imageNamed: String!, currentPiece: Type) {
    let color = UIColor()
    let texture = SKTexture(imageNamed: imageNamed)
    let size = CGSizeMake(100.0, 100.0)
    self.init(texture: texture, color: color, size: size)
    self.piecetype = currentPiece
}

在Swift中，便利初始化程序必须：

In Swift, a convenience initializer must:

• 调用同一类的另一个便利初始值设定项或类的指定初始值设定项（不是超类）


• 仅在致电 self.init [...]

• Call another convenience initializer of the same class or the designated initializer of the class (not the superclass)
• Use self only after calling self.init[...]

请参阅有关初始化程序的Swift文档以获取帮助： https://developer.apple.com/library/prerelease/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Initialization.html#//apple_ref/doc/uid/TP40014097- CH18-XID_323

See the Swift Documentation on initializer for help: https://developer.apple.com/library/prerelease/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Initialization.html#//apple_ref/doc/uid/TP40014097-CH18-XID_323

希望这有帮助，

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