Discussion
議論
Use this initializer to create a text field that binds to a bound optional value, using a ParseableFormatStyle
to convert to and from this type. Changes to the bound value update the string displayed by the text field. Editing the text field updates the bound value, as long as the format style can parse the text. If the format style can’t parse the input, the text field sets the bound value to nil
.
Use the onSubmit(of:_:)
modifier to invoke an action whenever the user submits this text field.
The following example uses an optional Double
as the bound currency value, and a FloatingPointFormatStyle.Currency
instance to convert to and from a representation as U.S. dollars. As the user types, a View.onChange(of:_:)
modifier logs the new value to the console. If the user enters an invalid currency value, like letters or emoji, the console output is Optional(nil)
.
@State private var myMoney: Double? = 300.0
var body: some View {
TextField(
"Currency (USD)",
value: $myMoney,
format: .currency(code: "USD")
)
.onChange(of: myMoney) { newValue in
print ("myMoney: \(newValue)")
}
}