SwiftUI 如何给 Slider 一个最小值和最大值并在文本中显示其值？

Question

import SwiftUI

struct ContentView : View {
    var body: some View {
        PasswordGeneratorSettings(settingsConfiguration: PasswordGeneratorSettings.Settings.init(passwordLength: 20))
    }
}


struct PasswordGeneratorSettings : View {
    @State var settingsConfiguration: Settings
    struct Settings {
        var passwordLength = UInt()
    }
    var body: some View {
        NavigationView {
            List {
                Slider(value: $settingsConfiguration.passwordLength) { pressed in
                    Text("Password Length: \(settingsConfiguration.passwordLength)")
                }
                }.navigationBarTitle(Text("Settings"))
        }
    }
}

So I'm making a password generator and I want to start off with a slider with a minimum length of 1 and a maximum length of 512 with a label displaying it's value (As an integer) but this is all I got to just try having an updating label on the left of the tableview (List) with the slider on the right but this doesn't even compile.

Too Long Didn't Read: I'm trying to:

1. Figure out how to set a minimum and maximum value with a Slider

2. Have a label with the Slider's value (as an integer) on the left side of a tableview cell with the slider on the right side.

And I want to do all of this without UIKit just SwiftUI (and Combine if needed).

Answer 1

This is how you use a slider:

import SwiftUI

struct ContentView : View {
    @State var length: Float = 20

    var body: some View {
        NavigationView {
            List {
                PasswordGeneratorSettings(length: $length)
            }.navigationBarTitle(Text("Settings"))
        }
    }
}


struct PasswordGeneratorSettings : View {
    @Binding var length: Float

    var body: some View {

        VStack(alignment: .leading) {
            Slider(value: $length, in: 1...512, step: 1)

            Text("Password Length: \(Int(length))")

        }
    }
}

Answer 2

Your code doesn't compile because you need to use double in the slider value parameter. You can achieve your requirement using the below code. Slider takes three parameter value, from and through. In simple language, from is minValue, through is maxValue and at any given time "value" will return current value in the slider.

struct PasswordGeneratorSettings : View {
    @State var settingsConfiguration: Settings
    struct Settings {
        var passwordLength: Double = 1.0
    }
    var body: some View {
        NavigationView {
            List {
                HStack {
                    Text("Password Length: \(Int(settingsConfiguration.passwordLength))")
                    Slider(value: $settingsConfiguration.passwordLength, from: 1, through: 512)
                }
                .padding()
            }.navigationBarTitle(Text("Settings"))
        }
    }
}

Answer 3

struct BoundsSlider : View {
    let min: CGFloat
    let max: CGFloat
    
    @Binding var value: CGFloat
    @State var lastValue: CGFloat
    
    init (min: CGFloat, max: CGFloat, value: Binding<CGFloat>) {
        self.min = min
        self.max = max
        _value = value
        _lastValue = State(initialValue: value.wrappedValue)
    }
    
    var body: some View {
        Slider(value: Binding.init(get: { () -> CGFloat in return value },
                                   set: { (newValue) in if true { value = newValue; lastValue = newValue } }), in: min...max)
    }
}

usage:

BoundsSlider(min: 0.7, max: 5, value: $speed)