重新开始复习前面的东西。

滑块Picker

.pickerStyle(SegmentedPickerStyle())

保留两位小数

Text("$ \(finalmon, specifier: "%.2f")")

代码

ContentView.swift

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//
//  ContentView.swift
//  Practise2-1
//
//  Created by 张洪Hoo on 2020/3/29.
//  Copyright © 2020 张洪Hoo. All rights reserved.
//

import SwiftUI

struct ContentView: View {
    @State private var amount = ""
    @State private var picknum = 1
    @State private var tip = 20
    
    var finalmon: Double {
        let amount = Double(self.amount) ?? 0
        let picknum = Double(self.picknum)
        let tip = Double(self.tip)
        
        let alltip = amount * tip / 100
        let allmon = amount + alltip
        let average = allmon / picknum
        
        return average
    }
    
    let tipmoney = [10,15,20,25,0]
    
    
    var body: some View {
        
        NavigationView {
            Form {
                Text("Hello world")
                TextField("Amount", text: $amount)
                    .keyboardType(.numberPad)
                
                Section {
                    Picker(selection: $picknum, label: Text("选择人数")) {
                        ForEach(1..<100, id: \.self){ item in
                            Text("\(item) 人")
                        }
                    }
                }
                
                Section(header: Text("How much tip do you want to leave ?")) {
                    Picker(selection: $tip, label: Text("Picker")) {
                        ForEach(self.tipmoney, id: \.self){ item in
                            Text("\(item)%")
                        }
                    }.pickerStyle(SegmentedPickerStyle())
                }
                
                Section {
                    Text("$ \(finalmon, specifier: "%.2f")")
                }
            }
            .navigationBarTitle(Text("WeSplit"))
        }
        

        
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

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