编辑代码

var myString = "Hello world!     -  swift.jsrun.net"
print(myString)


import UIKit
class ViewController: UIViewController ,UINavigationControllerDelegate,UIImagePickerControllerDelegate {
    //设置图像显示用的Outlet,就是变量carImageView
    @IBOutlet weak var carImageView: UIImageView!
    //设置Action,由相册按钮事件触发
    @IBAction func onLibrary(_ sender: UIButton) {
        //设置相册拍照的控制器
        let vc = UIImagePickerController()
        //设置为相册
        vc.sourceType = .photoLibrary 
        vc.allowsEditing = true 
        vc.delegate = self
        present(vc, animated: true)
        //设置Action,由拍照按钮事件触发
        @IBAction func onCamera(_ sender: UIButton) {
            let vc = UIImagePickerController()
            //设置为摄像头
            vc.sourceType = .camera 
            vc.allowsEditing = true 
            vc.delegate = self present(vc, animated: true)
        }
        //相册获取图片需要调用的Delegate
        func imagePickerController(_ picker: UIImagePickerController,didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey: Any]) {
            picker.dismiss(animated: true)
            guard let image = info[.editedImage] as? UIImage 
            else {
                return
            }
            //将相册图片显示在carImageView中 
            carImageView.image = image
        }
    }

//修改视图颜色
Rectangle()
        .foregroundColor(.blue)
        .border(.green) 

//视图/文本放置代码
import SwiftUI

struct IntroView:  View {
    var body: some View {
        HStack{//容器,用于水平放置容器内元素
               Image("FriendAndGem")
                   .resizable(capInsets: EdgeInsets(), resizingMode: .stretch)//使图片拉伸适应屏幕尺寸//
                   .scaledToFit()//图片适应界面大小,tofill为充满界面//
               Text("欢迎来到环保手工厂")
               Text("我是新 Text 元素。")
        }
    }
}


struct IntroView_Previews: PreviewProvider {
    static var previews: some View {
        VStack {//容器,用于垂直放置容器内元素//可与上一个容器嵌套使用
            IntroView()
            Text("欢迎来到环保手工厂")
            .font(.largeTitle)//字体设置,括号内为实参输入
        }
    }
}



//创建模型
var model = Model.allowsEditing

//将模型添加至场景
scene.add(model)
scene.setOnSttartHandler{
    model.animate ()
}


//飞蛾在5cm处跟随摄像头
var moth = Model.flyingBug
var snail = Model.snail

scene.add([snail,moth])

//让模型紧跟摄像头的代码
scene.setOnStartHandler {
    moth.follow(scene.camera.node, at: 5.cm)
}

//模型逃离摄像头
scene.camera.when(snail, isWithin: 10.cm) {
    snail.flee(from: scene.camera.node, safeDistance: 20.cm)
}