Swift学习笔记五

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Project 11 Pachinko

  1. SpriteKit 的point 0,0 表示某一个node的水平、竖直的中心点，Y坐标起始于底部，Y越大，在屏幕的位置越靠上。
    didMoveToView() 类似于 viewDidLoad()

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    let background = SKSpriteNode(imageNamed: "background.jpg")
    background.zPosition = -1        // behind everything else
    background.blendMode = .Replace	// just draw it, ignoring any alpha values
    addChild(background)
    physicsBody = SKPhysicsBody(edgeLoopFromRect: frame) //给整个屏幕添加PhysicsBody

  2. 在屏幕点击处绘制一个box，包括颜色、大小、physicsBody

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    override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
          if let touch = touches.first {
              let location = touch.locationInNode(self)
              let box = SKSpriteNode(color: UIColor.redColor(), size: CGSize(width: 64, height: 64))
              box.position = location
              box.physicsBody = SKPhysicsBody(rectangleOfSize: CGSize(width: 64, height: 64))
              addChild(box)
          }
      }

  3. 被碰撞后不会被移动

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    bouncer.physicsBody!.dynamic = false

  4. 设置旋转动作，包括弧度、时间间隔。

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    let spin = SKAction.rotateByAngle(CGFloat(M_PI_2), duration: 10)	// 每隔10秒旋转90°
    let spinForever = SKAction.repeatActionForever(spin)		// 永不停止
    slotGlow.runAction(spinForever)

  5. physicsBody的 contactTestBitMask 赋值给 collisionBitMask

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    physicsWorld.contactDelegate = self
    ball.physicsBody!.collisionBitMask = ball.physicsBody!.contactTestBitMask

  6. 将一个node移除 SKNode.removeFromParent()

  7. 判断接触的bodyA和bodyB

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    func didBeginContact(contact: SKPhysicsContact) {	//override
        if contact.bodyA.node!.name == "ball" {
            collisionBetweenBall(contact.bodyA.node!, object: contact.bodyB.node!)
        } else if contact.bodyB.node!.name == "ball" {
            collisionBetweenBall(contact.bodyB.node!, object: contact.bodyA.node!)
        }
    }

  8. 使用 didSet 属性观察器

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    var scoreLabel: SKLabelNode!  		
    var score: Int = 0 {
         didSet {
            scoreLabel.text = "Score: \(score)"
         }
    }
    let objects = nodesAtPoint(location) as [SKNode] // 获取到location的nodes

  9. 使用 GKRandomDistribution 方法设置随机数的上限、下限

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    let size = CGSize(width: GKRandomDistribution(lowestValue: 16, highestValue: 128).nextInt(), height: 16)   //生成16-128的Int类型随机数
    box.zRotation = RandomCGFloat(0, max: 3)  //随机的旋转，0-3的范围

  10. 使用 SKEmitterNode 方法，火焰粒子效果

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    if let fireParticles = SKEmitterNode(fileNamed: "FireParticles") {
         fireParticles.position = ball.position
         addChild(fireParticles)
    }

Project 12 NSUserDefaults

  1. as? 和 ?? 的用法

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    let array = defaults.objectForKey("SavedArray") as? [String] ?? [String]()

  2. 使用 NSUserDefault 需要遵守 NSCoding 协议

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    required init(coder aDecoder: NSCoder) {	//  required表示必须要实现这个方法
        name = aDecoder.decodeObjectForKey("name") as! String   // 解密
        image = aDecoder.decodeObjectForKey("image") as! String
    }
    // 加密
    func encodeWithCoder(aCoder: NSCoder) {
        aCoder.encodeObject(name, forKey: "name")
        aCoder.encodeObject(name, forKey: "image")
    }

  3. 将 array 类型转换为 NSData 类型。

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    func save() {
        //   converts array into an NSData object
        let savedData = NSKeyedArchiver.archivedDataWithRootObject(people)
        let defaults = NSUserDefaults.standardUserDefaults()
        defaults.setObject(savedData, forKey: "people")
    }

  4. 取出optional NSData，convert it back to an object graph

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    let defaults = NSUserDefaults.standardUserDefaults()
    if let savedPeople = defaults.objectForKey("people") as? NSData {
         people = NSKeyedUnarchiver.unarchiveObjectWithData(savedPeople) as! [Person]
    }

  5. NSUserDefaults是不安全的，如果涉及私密信息，可以用keychain替代.

    Project 13 Instafilter

  6. 使用 CIContext CIFilter

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    context = CIContext(options: nil)
    currentFilter = CIFilter(name: “CISepiaTone")

  7. 使用 CIImage

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    let beginImage = CIImage(image: currentImage)
    currentFilter.setValue(beginImage, forKey: kCIInputImageKey)

  8. 将 CGImage 转换为 UIImage

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    func applyProcessing() {
        currentFilter.setValue(intensity.value, forKey: kCIInputIntensityKey)
        let cgimg = context.createCGImage(currentFilter.outputImage!, fromRect: currentFilter.outputImage!.extent)
        let processedImage = UIImage(CGImage: cgimg)
        imageView.image = processedImage
    }

  9. presentViewController(xxxxx, animated: true, completion: nil) 把其中的xxxxx写成self导致运行时错误。

  10. UIImagePickerControllerEditedImage 少写Picker导致import图片后，无法继续操作。

  11. 先判断input keys 是否存在，然后判断是否包括 kCIInputIntensityKey

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    let inputKeys = currentFilter.inputKeys
    if inputKeys.contains(kCIInputIntensityKey) {
         currentFilter.setValue(intensity.value, forKey: kCIInputIntensityKey)
    }

  12. 将 imageView 写入图片库

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    UIImageWriteToSavedPhotosAlbum(imageView.image!, self, "image:didFinishSavingWithError:contextInfo:", nil)

  13. 写入图片库时的错误处理，使用 NSError，localizedDescription 显示具体的错误信息。

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    func image(image: UIImage!, didFinishSavingWithError error: NSError?, contextInfo: UnsafePointer<Void>) {

         let ac = UIAlertController(title: "Save error!", message: error?.localizedDescription, preferredStyle: .Alert)
         ac.addAction(UIAlertAction(title: "OK", style: .Default, handler: nil))
         presentViewController(ac, animated: true, completion: nil)
    }