本文價值與收獲

看完本文后，您將能夠作出下面的界面

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Jietu20200419-171132.gif

看完本文您將掌握的技能

• 掌握Picker基礎使用
• 類似alert的調用模式
• 獲取響應數據
• 學會使用ViewModifier
• 學會fileprivate
• 學會使用extention

代碼

1、主頁面代碼

import SwiftUI

struct ContentView: View,Picker_Image_Pro {

    @State var isShow = false
    @State var fruit = "選擇水果"
    var body: some View {
        VStack{
            Spacer()
            Button("\(self.fruit)"){
                self.isShow.toggle()
            }
            //為了測試背景模糊
            List{
                ForEach(1..<20){ item in
                    Text("\(item)")
                }
            }
            Spacer()
        }
        //鏈式調用效果
        .showPicker(isPresented: self.$isShow,delegate: self)
            
    }
    //選擇后響應函數
    func pickerSelect(selectItem: String) {
        self.fruit = "選擇的水果:"+selectItem
    }
    
}

2、制作個view 擴展

extension View {
    
    func showPicker(isPresented: Binding<Bool>,delegate:Picker_Image_Pro) -> some View {
        
        self.modifier(PickerVM(isPresented: isPresented,delegate: delegate))

    }

}

3、制作個modifier

struct PickerVM: ViewModifier {
    @Binding var isPresented: Bool
    var delegate:Picker_Image_Pro
    func body(content: Content) -> some View {
        
        ZStack {
            content
            .disabled(self.isPresented)
                               .blur(radius: self.isPresented ? 6 : 0)
            if isPresented {
                Picker_Image(isPresented: self.$isPresented,delegate: self.delegate)
                .zIndex(1)
          
            }
        }
  
    }
    
}