✨.currency

💾 程式

📗 參考：Paul ⟩ Reading text from the user with TextField

struct WeSplitApp: View {
    
    @State private var checkAmount = 0.0        // Double
    
    var body: some View {
        
        // ⭐️ 當地貨幣碼：Locale.current.currencyCode
        let code = Locale.current.currencyCode ?? "USD"    // TWD
        
        // ⭐️ FloatingPointFormatStyle<Value>.Currency
        let currency: FloatingPointFormatStyle<Double>.Currency = 
            .currency(code: code)
        
        NavigationView {
            Form {
                Section {
                    TextField(
                        "Amount", 
                        value: $checkAmount, 
                        format: currency        // ⭐️ 數字格式：貨幣
                    )
                    // ---------------------------------------------------
                    // ❗️ this won't stop users from entering other values
                    //   if they have a hardware keyboard or 
                    //   if they copy/paste text from elsewhere.
                    // ---------------------------------------------------
                    .keyboardType(.decimalPad)    // ⭐️ 數字鍵盤
                }
                
                Section {
                    Text(checkAmount, format: currency)// ⭐️ 數字格式：貨幣
                }
            }
            .navigationTitle("We Split")
            .navigationBarTitleDisplayMode(.inline)
        }
    }
}

📘 手冊

• Foundation ⟩

  • Data Formatting ⟩

    • Locale (struct)

    • FormatStyle (protocol) ⭐️

      • ParseableFormatStyle (protocol)

        • FloatingPointFormatStyle<Value> (generic struct) ⭐️

          • FloatingPointFormatStyle.Currency

            • .currency<Value>(code:) where Value : BinaryFloatingPoint

• SwiftUI ⟩ Text Input and Output ⟩ TextField ⟩

  • .init(_:value:format:prompt:) ⭐️ create a text field that binds to a bound value, using a ParseableFormatStyle to convert to and from this type.

👥 相關

History

✏️

1. 2022.03.31

1

struct WeSplitApp: View {
    
    @State private var checkAmount = 0.0
    @State private var numberOfPeople = 2
    @State private var tipPercentage = 20
    
    let tipPercentages = [10, 15, 20, 25, 0]
    
    var body: some View {
        NavigationView {
            Form {
                Section {
                    // ⭐️ TextField with format
                    TextField(
                        "Amount", 
                        value: $checkAmount, 
                        format: .currency(code: Locale.current.currencyCode ?? "USD")
                    )
                    // ---------------------------------------------------
                    // ❗️ this won't stop users from entering other values
                    //   if they have a hardware keyboard or 
                    //   if they copy/paste text from elsewhere.
                    // ---------------------------------------------------
                    .keyboardType(.decimalPad)
                }
                
                Section {
                    Text(checkAmount, format: .currency(code: Locale.current.currencyCode ?? "TWD"))
                }
            }
            .navigationTitle("We Split")
            .navigationBarTitleDisplayMode(.inline)
        }
    }