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Accepted
Unofficial Cuber
Asked: 2024-11-21 21:54:41 +0800 CST

无法将类型“Range<Int>”的值转换为预期参数类型“Binding<C>”

  • 772

我正在用 Swift 制作一个应用，用户必须回答一个问题。可以接受多个答案，因此我使用 ForEach 循环来检查所有答案。但是，当我尝试切换“正确”变量时（因此“正确！”消息仅显示一次），我收到错误（见标题）。错误显示在第 77 行：ForEach(0..<data.answer.count, id: .self)。有人知道如何修复这个问题吗？？？

import SwiftUI

struct LocationView: View {
    @State private var submit: Bool = false
    @State private var guess = ""
    @State private var correct = false
    var data: Location
    
    var body: some View {
            Text(data.question)
                .padding()
            
            TextField("Answer", text: $guess)
                .padding()
                .overlay(
                    RoundedRectangle(cornerRadius: 10)
                        .stroke(Color.green, lineWidth: 2)
                )
                .padding()
            
            Button(action: {
                submit.toggle()
            }) {
                Text("Submit")
                    .foregroundStyle(.blue)
                    .font(.headline)
            }
            
            if submit {
                ForEach(0 ..< data.answer.count, id: \.self) { answer in
                    if guess == data.answer[answer] {
                        correct.toggle()
                    }
                }

                if correct {
                    Text("Correct!")
                        .foregroundStyle(.green)
                        .font(.headline)
                }
            }
        }
    }
}

#Preview {
    let modelData = ModelData()
    LocationView(data: modelData.locations[0])
}
swift

1 个回答

  1. Best Answer

    ForEach 用于从集合创建视图。您没有在 foreach 中提供任何视图，它不是仅用于计算的正确位置。

    我已将验证正确答案和更改提交状态的计算移至按钮单击操作

    struct Location {
    let question: String
    let answer: [String]
}

struct LocationView: View {
    @State private var submitted: Bool = false
    @State private var guess = ""
    @State private var correct = false
    var data: Location
    
    var body: some View {
        question
        answer
        submitButton
        if submitted {
            message
        }
    }
    
    var question: some View {
        Text(data.question)
            .padding()
    }
    
    var answer: some View {
        TextField("Answer", text: $guess)
            .padding()
            .overlay(
                RoundedRectangle(cornerRadius: 10)
                    .stroke(Color.green, lineWidth: 2)
            )
            .padding()
            .disabled(!guess.isEmpty && submitted)
    }
    
    var submitButton: some View {
        Button(action: onSubmit) {
            Text("Submit")
                .foregroundStyle(.blue)
                .font(.headline)
        }
    }
    
    var message: some View {
        Group {
            if correct {
                Text("Correct!")
                    .foregroundStyle(.green)
            } else {
                Text("Wrong")
                    .foregroundStyle(.red)
            }
        }
        .font(.headline)
        .transition(.scale)
    }
    
    func onSubmit() {
        if !guess.isEmpty {
            withAnimation {
                submitted = true
                verifyAnswer()
            }
        }
    }
    
    func verifyAnswer() {
        correct = data.answer.contains(guess)
    }
}

#Preview {
    LocationView(data: Location(question: "guess number?", answer: ["one", "two", "three"]))
}
    • 1

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