SwiftUI TextField中的货币输入

import SwiftUI

struct ContentView: View {
    @State private var amount: Double = 0.0
    
    var body: some View {
        VStack {
            TextField("Amount", value: $amount, formatter: CurrencyFormatter())
                .textFieldStyle(RoundedBorderTextFieldStyle())
                .padding()
            
            Text("Formatted Amount: \(CurrencyFormatter().string(for: amount) ?? "")")
                .padding()
        }
    }
}

struct CurrencyFormatter: Formatter {
    init() {
        numberFormatter.numberStyle = .currency
        numberFormatter.maximumFractionDigits = 2
    }
    
    let numberFormatter = NumberFormatter()
    
    func string(for obj: Any?) -> String? {
        guard let amount = obj as? Double else { return nil }
        return numberFormatter.string(from: NSNumber(value: amount))
    }
    
    func getObjectValue(_ obj: AutoreleasingUnsafeMutablePointer<AnyObject?>?, for string: String, errorDescription error: AutoreleasingUnsafeMutablePointer<NSString?>?) -> Bool {
        if let number = numberFormatter.number(from: string) {
            obj?.pointee = number
            return true
        } else {
            return false
        }
    }
}

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