弹出Sheet视图 - MVVM模式
=======================
## 知识点
* 采用MVVM模式, 循环数据并弹出Sheet视图
## 实战演习
### AppData.swift
~~~swift
////////////////////////////////////
// 弹出Sheet视图 - MVVM模式
//
// 小马视频频道
// http://komavideo.com
////////////////////////////////////
import SwiftUI
struct Hero {
var name: String
var showname: String
var attack: Int
}
struct HeroViewModel: Identifiable {
var id = UUID()
var hero: Hero
var desc: String {
return "英文名：" + hero.name + "／攻击力：\(hero.attack)"
}
}
class AppData: ObservableObject {
@Published var heroes: [HeroViewModel]
init() {
self.heroes = [
HeroViewModel(hero: Hero(name: "8bit", showname: "8比特", attack: 5)),
HeroViewModel(hero: Hero(name: "barley", showname: "巴里", attack: 3)),
HeroViewModel(hero: Hero(name: "bea", showname: "蜜蜂", attack: 5)),
HeroViewModel(hero: Hero(name: "bibi", showname: "芘芘", attack: 4)),
]
}
}
~~~
### ContentView.swift
~~~swift
import SwiftUI
struct HeroView: View {
@Environment(\.presentationMode) var presentation
let herovm: HeroViewModel
var body: some View {
VStack {
Spacer()
Text(herovm.hero.showname)
.font(.largeTitle)
Image(herovm.hero.name)
.resizable()
.frame(width: 330, height: 250)
.cornerRadius(20)
Text(herovm.desc)
Spacer()
Button("关闭") {
self.presentation.wrappedValue.dismiss()
}.font(.title)
}
}
}
struct ContentView: View {
@EnvironmentObject var appData: AppData
@State private var openSheet: HeroViewModel? = nil
var body: some View {
List {
ForEach(self.appData.heroes) { vm in
HStack {
Image(vm.hero.name)
.resizable()
.frame(width: 50, height: 50)
.cornerRadius(15)
Button(action: {
self.openSheet = vm
}, label: {
Text(vm.hero.showname)
})
}
}
}
.sheet(item: self.$openSheet) { vm in
HeroView(herovm: vm)
}
}
}
~~~
### myappApp.swift
```swift
import SwiftUI
@main
struct myappApp: App {
@StateObject var appData: AppData = AppData()
var body: some Scene {
WindowGroup {
ContentView()
.environmentObject(self.appData)
}
}
}
```
## 课程文件
https://github.com/komavideo/LearnSwiftUI
## 小马视频频道
http://komavideo.com
LearnSwiftUI-master.zip （30个子文件） 
LearnSwiftUI-master Lesson21 
README.md 3KB Lesson17 README.md 1KB Lesson14 README.md 1KB Lesson18 README.md 1KB Lesson11 README.md 1KB Lesson26 README.md 859B Lesson02 README.md 1KB Lesson01 README.md 1019B Lesson22 README.md 1KB Lesson10 README.md 2KB Lesson15 README.md 1KB Lesson19 README.md 1KB Lesson06 README.md 1001B Lesson20 README.md 1KB Lesson27 README.md 2KB Lesson04 README.md 1KB Lesson24 README.md 2KB Lesson25 README.md 2KB Lesson08 README.md 1KB Lesson23 README.md 957B Lesson09 
mvvm-pattern.png 12KB README.md 1KB Lesson07 README.md 2KB Lesson05 README.md 1KB Lesson16 README.md 2KB README.md 1KB Lesson13 README.md 2KB Lesson03 README.md 1017B Lesson12 README.md 2KB
说明.pdf 22KB资源评论
