在没有 NumberFormatter 的情况下停止 TextField 中的字符重复 [英] Stop character repetition in TextField without NumberFormatter

问题描述

例如在文本字段中，我希望能够重复所有数字，但用户应该只能使用一次小数点.所以，用户不应该能够做:12...4"；但应该只能做一次12.4".有什么特别的方法可以做到吗?是否可以在不使用 UIKit 的情况下使用 SwiftUI 来完成?

For example in a textfield I want to be able to repeat all numbers, but user should be able to use decimal point only once. So, the user should not be able to do: "12...4" but should only be able to do it once "12.4". Any particular way to do do it? Is it possible to do it with SwiftUI without using UIKit?

import SwiftUI
import Combine

struct TipsView: View {
    @State private var amount = ""
    
    var body: some View {
        NavigationView {
            Form {
                Section (header: Text("Amount")) {
                    HStack (spacing: 1) {
                        Text("£")
                        TextField("Amount", text: $amount)
                            .onReceive(Just(amount)) { _ in
                                
                            }
                    }
                }
            }
        }
    }
}

推荐答案

我使用了字符串分隔符将输入字符串分成两个不同的数组.意思是，一个数组包含小数点前的值，另一个数组包含小数点后的值.

I have used a String separator to separate the input string into two different arrays. Meaning, one array would contain values before the decimal point and the other would contain values after the decimal point.

import SwiftUI

struct DecimalView: View {
    @State private var amount = ""
    var body: some View {
        Form {
            Section(header: Text("Amount")) {
                HStack {
                    Text("£")
                    TextField("Enter amount", text: $amount)
                        .onChange(of: amount) { _ in
                            let filtered = amount.filter {"0123456789.".contains($0)}
                            
                            if filtered.contains(".") {
                                let splitted = filtered.split(separator: ".")
                                if splitted.count >= 2 {
                                    let preDecimal = String(splitted[0])
                                    let afterDecimal = String(splitted[1])
                                    amount = "\(preDecimal).\(afterDecimal)"
                                }
                            }
                        }
                }
            }
        }
    }
}

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