作業7#91 自訂 controller 類別和利用 viewDidLoad 客製 App 畫面

運用了

1. 利用 CAGradientLayer 製作漸層
2. 利用 mask 設計特別形狀的圖片
3. 使用 SwiftUI 的 live preview 即時預覽 CAEmitterLayer＆製作下雪動畫
4. 播放背景音樂

import SwiftUI
import UIKit
import AVFoundation
class ViewController: UIViewController {
    //播放音樂的播放器
    let player = AVPlayer()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view
        //漸層背景
        let gradientLayer = CAGradientLayer()
        gradientLayer.frame = CGRect(x: 0, y: 0, width: 414, height: 896)
        gradientLayer.colors = [
            CGColor(red: 197/255, green: 227/255, blue: 215/255, alpha: 1),
            CGColor(red: 139/255, green: 220/255, blue: 215/255, alpha: 1),
            CGColor(red: 255/255, green: 154/255, blue: 168/255, alpha: 1),
            CGColor(red: 255/255, green: 119/255, blue: 105/255, alpha: 1)
        ]
        view.layer.addSublayer(gradientLayer)
       
        //聖誕樹
        let christmasTreeImage = UIImageView(frame: CGRect(x: 10, y: 200, width: 399, height: 499))
        view.addSubview(christmasTreeImage)
        let animatedImage = UIImage.animatedImageNamed("christmas-tree-christmas-decorations-", duration: 1)
        christmasTreeImage.image = animatedImage
        
        //字
        let messageLabel = UILabel(frame: CGRect(x: 30, y: 750, width: 400, height: 50))
               messageLabel.text = "Merry Chrismas"
               messageLabel.font = UIFont.boldSystemFont(ofSize: 50)
               messageLabel.textColor = UIColor(red: 0/255, green: 136/255, blue: 168/255, alpha: 1)
               view.addSubview(messageLabel)
        
        //雪花動畫
        let snowEmitterCell = CAEmitterCell()
        snowEmitterCell.contents = UIImage(named: "snow")?.cgImage
        snowEmitterCell.birthRate = 2
        snowEmitterCell.lifetime = 15
        snowEmitterCell.velocity = 100
        snowEmitterCell.scale = 0.5
        snowEmitterCell.scaleRange = 0.3
        snowEmitterCell.spin = 0.5
        snowEmitterCell.spinRange = 1
        snowEmitterCell.yAcceleration = 30
        snowEmitterCell.emissionRange = CGFloat.pi
        
        let snowEmitterLayer = CAEmitterLayer()
        snowEmitterLayer.emitterCells = [snowEmitterCell]
        snowEmitterLayer.emitterPosition = CGPoint(x: 200, y: 0)
        snowEmitterLayer.emitterSize = CGSize(width: 414, height: 896)
        snowEmitterLayer.emitterShape = .line
        view.layer.addSublayer(snowEmitterLayer)
        
        //星星動畫
        let starEmitterCell = CAEmitterCell()
        starEmitterCell.contents = UIImage(named: "star")?.cgImage
        starEmitterCell.birthRate = 5
        starEmitterCell.lifetime = 2
        starEmitterCell.velocity = 50
        starEmitterCell.scale = 0.5
        starEmitterCell.scaleRange = 0.2
        starEmitterCell.yAcceleration = 30
        let starEmitterCellLayer = CAEmitterLayer()
        starEmitterCellLayer.emitterCells = [starEmitterCell]
        starEmitterCellLayer.emitterPosition = CGPoint(x: 0, y: 100)
        starEmitterCellLayer.emitterSize = CGSize(width: 800, height: 300)
        starEmitterCellLayer.emitterShape = .line
        view.layer.addSublayer(starEmitterCellLayer)
        
        //樹星
        let treeStarImage = UIImage(named: "treestar")
        let treeStarImageView = UIImageView(image: treeStarImage)
        treeStarImageView.frame = CGRect(x: 175, y: 165, width: 64, height: 64)
        let treeStarBackImage = UIImage(named: "treestarback")
        let treeStarBackImageView = UIImageView(image: treeStarBackImage)
        treeStarBackImageView.frame = treeStarImageView.frame
        treeStarImageView.frame.origin = .zero
        treeStarBackImageView.mask = treeStarImageView
        view.addSubview(treeStarBackImageView)
        
     //音樂
        let fileUrl = Bundle.main.url(forResource: "LastChristmas", withExtension: "mp3")!
        let playerItem = AVPlayerItem(url: fileUrl)
        player.replaceCurrentItem(with: playerItem)
        player.play()
        player.pause()
        
        
        
        
        
    }
}
struct ViewControllerView: UIViewControllerRepresentable {
    func makeUIViewController(context: Context) -> ViewController {
        ViewController()
    }
    
    func updateUIViewController(_ uiViewController: ViewController, context: Context) {
    }
    
    typealias UIViewControllerType = ViewController
    
    
}
struct ViewController_Previews: PreviewProvider {
    static var previews: some View {
        ViewControllerView()
    }
}