Swift UI: Data Binding & Alert 練習

Source: Unplashed

可以花在這次作業的時間沒有很多，Peter 老師我對不起你…

內容：

1. Alert 功能
2. Slider 功能

1.Alert 功能

Alert 功能

@State private var showAlert = false
       var body: some View {
          Button(action: {
             self.showAlert = true
          }) {
             VStack {
                Image("Carol2019")
                   .renderingMode(.original)
                Text("你還愛我嗎")
             }
          }.alert(isPresented: $showAlert) { () -> Alert in
             let answer = ["愛", "不愛"].randomElement()!
             return Alert(title: Text(answer))
          }
        }
     }

2.Slider 功能

Binding & State 功能

struct EditPhotoView: View {
    
    @State private var brightnessAmount: Double = 0
    //加入代表圖片亮度的 state property brightnessAmount
    @State private var selectDate = Date()
    @State private var selectBlend = BlendMode.screen
let today = Date()
    let startDate =
        Calendar.current.date(byAdding: .year, value: -2,to: Date())!
    var year: Int {Calendar.current.component(.year, from:selectDate)
    }
    let blendModes: [BlendMode] =
[.screen, .colorDodge, .colorBurn]
    var body: some View {
        
        
        GeometryReader {geometry in
            VStack {
                ZStack {
                Image("pattern")
                    .resizable()
                    .scaledToFill()
                    .frame(width: geometry.size.width, height:
                        geometry.size.width / 4 * 3)
                    .clipped()
                Image("Carol\(self.year)")
                .resizable()
                .scaledToFill()
                    .offset (y:50)    .frame(width:geometry.size.width,height:geometry.size.width/4*3) .clipped()
                    .brightness(self.brightnessAmount)
                    .blendMode(self.selectBlend)
             
            }
                Form{BrightnessSlider(brightnessAmount:self.$brightnessAmount)
                    DatePicker("時間",selection:self.$selectDate,in:self.startDate...self.today,displayedComponents:.date)
                }
        }
    }
}

(2) 特製的 App 畫面截圖。

Github:https://github.com/00757306/Growing-Story